Potatoes

Potatoes

Growing Potatoes

Earlies

Warba (f)*, Carlton (f), Rocket (f), Eramosa (f), Epicure (f).

Whites, Early/Mid/Late

AC Ptarmigan (f&p), Norchip (f&p), White Rose (f), Shepody (f&p), Atlantic (f&p), Cascade (f&p), CalWhite (f&p), Cherokee (f&p), NorValley (f&p), Kennebec (f&p), Chipeta (p), Snowden (p).

*Best end use: f = fresh; p = process

Russets, Mid-season

Norgold Russet (bo&ba)**, Russet Norkotah (bo&ba), Hilite Russet (ff&ba), Goldrush (ff,bo&ba), Norqueen (ff,bo&ba)

Russets, Late

Ranger Russet (ff&ba), Russet Legend (ff,bo&ba), Gem Russet (ff,bo&ba), Umatilla Russet (ff,bo&ba), Russet Burbank (ff,bo&ba), Nooksack (ff,bo&ba).

**Best end use: ba = bake, bo = boil, ff = French fry.

Red-skinned

Norland (Dark Red), Redsen, Red Ruby, CalRed, NorDonna, Red Pontiac, Viking, Chieftain, Sangre, Ida Rose, Red La Soda

Yellow-fleshed

Yukon Gold, Sante, Sieglinde, Bintje

Red-skinned, Yellow-fleshed

Desiree.

In most areas of British Columbia, potatoes become infected with virus diseases unless special precautions are taken. The best way to avoid certain viruses and other diseases is to buy British Columbia grown certified seed potatoes. Certified seed potatoes are available in the following classes:

Elite III =  E III
Elite IV =  E IV
Foundation =  F
Certified  =  C

E III seed is normally used by seed growers to produce E IV seed. E IV seed is then used to produce Foundation seed. Foundation seed can be used to produce Certified seed or commercial table potatoes. Certified class seed is used for commercial planting only and cannot be used to produce a certified seed crop.

Earlier generation seed such as E III and E IV, when available, can be used for the planting of commercial table potatoes. Yields could be expected to be slightly higher as the seed is potentially freer of latent viruses compared to later generation seed (Certified). The earlier generation seed may be slightly more expensive.

In the production of seed potatoes, growers have to meet certification standards established by the Canadian Food Inspection Agency. Certification standards, as well as a list of seed potato growers, can be obtained by contacting us or the BC Certified Seed Potato Growers Association.

Always plant Foundation or Certified seed or better. Discard any tubers or seed-pieces showing decay. Store in cool storage (3 to 4°C) for the main storage season, but warm seed (10 to 13°C) for 2 weeks prior to planting. Cut seed should be planted immediately. If this is not possible stack in sacks or crates in a manner that allows air movement about them, then keep in a humid atmosphere for 2 or 3 days to ensure proper suberization.

 
Keep out of sun or hot, drying wind. Seed treatment reduces seed-piece decay and reduces seed spread of blackleg, late blight and common scab. It will not prevent soil-borne forms of these diseases. See specific disease sections below for rates of materials to use.

Seed is planted at an average depth of 10 cm. Approximately 1,800 kg of seed/ha is required if 50 g seed pieces are planted 30 cm apart in 90 cm rows. Spacing will vary according to variety and local conditions.

To provide the best natural scab control in coastal areas, a pH of 4.8 to 5.6 is usually adequate; in interior areas a pH below 6.5 is more desirable. In all cases, well-prepared, deep, open soils are required for planting.

Manures and Crop Residues

The growing of green-manure crops and the plowing-down of crop residues are necessary for retention of crop nutrients. Straw, corn stalks and occasionally grassy sod require additional nitrogen to aid breakdown of the material (i.e., 80 to 110 kg/ha (30 to 45 kg/acre) of 34-0-0 or equivalent).

Barnyard manures at rates of 22 to 45 tonnes/ha (10 to 20 tonnes/acre) or poultry manures at 11 to 18 tonnes/ha (5 to 7 tonnes/acre) provided they do not contain excessive amounts of shavings or sawdust, are desirable in that they provide extra nutrients and maintain organic matter. The best time for applying these is following plowing and during the final discing.

Where common scab is a problem, poultry manures should not be applied in the spring but may be safely applied the previous fall.

Fertilizers

A soil test is necessary to determine phosphate and potash requirements. Use the Vegetable Production Guide: Nutrient Management (PDF) for recommendations based on soil test results.

Nitrogen Recommendations for Potatoes

Soil Type Rate
Mineral Soil 70 kg/ha (28 kg/ac)
Organic Soil 50 kg/ha (20 kg/ac)
Arid Interior 90 kg/ha (36 kg/ac)
Creston Valley 100 kg/ha (40 kg/ac)
Bulkley Valley 60 kg/ha(25 kg/ac)

Russet Norkotah requires more initial fertilizer and the use of slow release nitrogen fertilizer may be of benefit.

If banding, apply the fertilizer treatment approximately 5 cm to the side and 5 cm below the seed piece. Where a magnesium deficiency is suspected, apply 45 kg/ha (18 kg/acre) magnesium (MgO).

Use of a sprout inhibitor will extend the storage life of potatoes. It is particularly useful if potatoes are held at warmer temperatures (8 – 10°C) for processing purposes. Several methods are possible (see following table).

Sprout Inhibition Treatment Prior to Harvest with Royal MH30 XTRA

Product Rate Comments

ROYAL MH30 XTRA 

(maleic hydrazide)

12.6 L/ha
(5.1 L/acre)

Apply in at least 300 L/ha (120 L/acre) of water
  • Do not apply ROYAL MH to potatoes to be used for seed purposes.
  • Apply ROYAL MH to potatoes within the period between two to three weeks past full bloom and two weeks before expected date of top kill or first frost.
  • Do not apply too early. Applications made prior to proper sizing of tubers can reduce yields. The majority of tubers should be at least 4 - 5 cm in diameter if they are to reach a minimum size of 110-170 grams (4 – 6 ounces) at harvest.
  • Uneven or excessive application may result in reduced efficacy and physical disorders such as bud end cracking and/or elephant hide.
  • Do not apply ROYAL MH after the upper leaves have turned from dark green to a light green or yellow colour as insufficient material will be absorbed and translocated from the leaves to the tubers – thus giving unsatisfactory sprout control.
  • Best results are obtained when ROYAL MH is applied under slow drying conditions (i.e. during early morning hours or on cloudy days).
  • Do not apply if daily temperatures are expected to exceed 30oC, as high temperatures and low humidity will cause the material to crystallize on the leaf surface and not be absorbed into the plant.
  • Apply at least 24 hours before rainfall or irrigation.
  • Do not spray when wind velocity exceeds 15 km/hr.

 

Sprout Inhibition Treatment in Storage With Sprout Nip

Product Rate Comments

SPROUT NIP EC

(chlorpropham)
Apply 900 mL of 1% emulsion per 20 bags of potatoes (45 kg per bag)
 
or:
 
Apply 25L of 1% emulsion per 25 metric tonnes of potatoes
  • Prepare 1% emulsion by adding 1 L of product to 35 L of water.  Stir to form a uniform emulsion.
  • Treatment normally occurs when 2 weeks have elapsed after harvest to allow tuber wounds to heal.
  • Apply to potatoes in the packing line.
  • Set spray nozzle in packing line between the cleaning equipment and the packing equipment.
  • In packing lines equipped with brushes, place the spray nozzle on the output side of the brushes.
  • In wash lines, place the spray nozzle on the output side of the dryer rolls.
  • A shield should be in place around the spray table/conveyor belt to prevent spray mist drift.
  • Contact with the buds on the tuber is essential.
  • Dirt on the potato may prevent product from reaching the buds.
  • Do not apply in the field.
  • Do not use on seed potatoes.
  • Store treated potatoes away from seed potatoes.
  • Do not put seed potatoes in bins which have been exposed to this material.
  • Thorough cleanup of storage bins is necessary following removal of potatoes — sweep out bins, wash crystallized material off machinery, fans, ducts and walls with alcohol or light oil, then hose out bins thoroughly with water and aerate.

Mechanical

Commercial mechanical top-beaters can be used to effectively beat off potato tops. Adjust height to beat off the tops without injuring tubers near the soil surface. This is the preferred method of top-kill for organic growers.

Where foliage is heavy it is best to apply a chemical vine-killer first, followed, just prior to harvest, by mechanical beating to shred tops. This combination treatment provides the most effective kill.

Chemical

Do not apply when plants are actively growing. Best results are obtained after growth has passed its peak and adequate skin set has begun. Apply one of the following sprays, preferably through drop pendant nozzles so as to provide thorough coverage of leaves and vines.

Chemical vine-killers

Product Rate Comments

Reglone Dessicant

(diquat ion)

Top growth light, few weeds or top growth heavy and in early stage of maturity:  

1.7 – 2.3 L/ha (0.7 – 0.9 L/acre)

 

Top growth or weedy field:  

3.5 L/ha (1.4 L/acre)


Apply in 550 – 1100 L/ha (220 – 440 L/acre) of water

  • Treatment is most effective when applied on cloudy days.
  • A second application may be required 4 – 6 days after the first at normal topkill time.
  • Use higher rate in the first application on denser or immature vines; a fungicide may be added.
  • Do not use with Agral 90.
  • For seed crops left in the ground, a followup Reglone application may be desired to topkill regrowth to prevent aphid buildup and subsequent virus infection.
  • Do not apply within 15 metres of sloughs, or migratory bird or wildlife habitats.
  • Do not apply to drought stressed plants.
  • Group 22 herbicides.

Dessicash Dessicant

(diquat ion)

Top growth light, few weeds or top growth heavy and in early stage of maturity:  

1.7 – 2.3 L/ha (0.7 – 0.9 L/acre)

 

Top growth or weedy field:  

3.5 L/ha (1.4 L/acre)


Apply in 550 – 1100 L/ha (220 – 440 L/acre) of water

  • Treatment is most effective when applied on cloudy days.
  • A second application may be required 4 – 6 days after the first at normal topkill time.
  • Use higher rate in the first application on denser or immature vines; a fungicide may be added.
  • Do not use with Agral 90.
  • For seed crops left in the ground, a followup Reglone application may be desired to topkill regrowth to prevent aphid buildup and subsequent virus infection.
  • Do not apply within 15 metres of sloughs, or migratory bird or wildlife habitats.
  • Do not apply to drought stressed plants.
  • Group 22 herbicides.

Aim EC

(carfentrazone-ethyl)

Group 14

233 to 350 mL/ha
(30 to 142 mL/acre)

Apply in 100 to 200 L/ha (40 to 80 L/acre) of water

  • Use with Agral 90 or Ag-Surf at 0.25% v/v or Merge at 1% v/v.
  • If a second burndown application is required, make a second application in 7 to 14 days, using the high rate.
  • Observe post-harvest interval of 7 days.

Beloukha

(Pelargonic acid)

Group 26

16 to 22 L/ha
(6.5 to 8.9 L/acre)

Apply in 300 L/ha (120 L/ac) of water
  • Apply at onset of senescence at least 2 weeks prior to harvest.
  • Note:  for especially dense foliage, apply in 1100 L/ha (445 L/ac) of water.
  • Repeat as needed in 7 to 14 days.
  • Use the low rate when using mechanical top beater.
  • Do not apply more than 2 times per season.
  • Do not apply if foliage is wet from dew or rain.
  • Leaf kill will be seen rapidly (1 to 7 days) with gradual vine death occurring 15 to 28 days after application.
  • Do not re-enter treated area until spray has dried.

Harvest potatoes for storage when tuber temperatures are below 15.5°C and above 7°C. Above 15°C, field heat causes quality deterioration in storage before cooling can occur. Below 7°C, potatoes will be bruised during harvest. If temperatures are too warm, harvesting should be done early in the day. Conversely, if temperatures are too cold, harvesting should start later in the day and continue into the evening.

Bruising can be further reduced by limiting fertilizer and irrigations toward the end of the season; initiating skin set through vine killing; conditioning the soil with a light irrigation; adjusting the harvester for proper ratio of chain and forward speeds; and keeping the harvester chain filled with potatoes.

 

Ideal storage conditions prevent the development of tuber rot organisms and maintain tuber quality. StorOx (formerly called Oxidate) can be applied to potatoes entering storage and added to humidification water during storage period. StorOx is registered as an in-storage treatment to control Fusarium Rot, Bacterial Soft Rot and Silver Scurf. StorOx is corrosive to metals; use nylon or poly nozzles instead of brass. Regular inspection of metallic equipment is advised if applying in storage through the humidification system. Follow label instructions carefully to avoid operator and environmental hazards.

When harvesting during warm temperatures, remove field heat from tubers in storage as rapidly as possible. Lower tuber temperature to 10°C, preferably within 3 days.

Higher temperatures are only advisable if it is necessary to encourage the breakdown of late blight infected tubers so that grading and shipping can proceed.

Maintain a wound healing temperature of 10°C with relative humidity (RH) above 95% for a month or longer, if possible. These are also the ideal storage conditions for potatoes to be processed into chips.

After the wound healing period, the pile temperature should be lowered by 1/3°C per day (approximately 2°C per week) to a holding level of:

  • 7 to 10°C for potatoes intended for french fries (7 to 8°C for Russet Burbank);
  • 4 to 7°C for fresh market potatoes; (7°C for Russet Burbank);
  • 3.5 to 4.5 °C for seed potatoes

A relative humidity of 95% is desirable for long term storage to maintain quality and minimize shrinkage.

To cool the potatoes, a ventilation rate of up to 20 cubic feet per minute (cfm) per ton of potatoes is required depending on the air temperatures available for ventilation. In the Lower Fraser Valley, both fall and winter temperatures may be too warm, especially for seed potatoes, therefore the highest practical ventilation rate of 20 cfm per ton should be used. In Pemberton, Vernon and other Interior B.C. locations, a ventilation rate of 12 to 15 cfm per ton is adequate.

Ambient air temperatures and daily hours of available cooling at harvest determine the cooling capacity of a ventilation system. The potatoes should be ventilated from ducts spaced on approximately 2.5 m centres. The temperature of the potato pile will tend to be about 1 °C cooler at the bottom than at the top.

While cooling warm potatoes try to use air saturated with moisture that is not too much colder than the potatoes. Air that is 3°C colder than the potatoes even when saturated will be lowered to approximately 82 % RH when it is warmed to the potato temperature, causing the potatoes to lose moisture. Therefore the potatoes should be cooled gradually with air that is just below the temperature of the potatoes and as moist as possible.

Once the potatoes have reached their long-term storage temperature, ventilation should be reduced to several hours per day or just enough to maintain pile temperature. It is not necessary to ventilate continuously unless ceiling condensation or rot development within the pile is a problem. Unnecessary ventilation can increase weight loss and quality change. Note that ventilation air should always be colder than the tubers during long-term storage, otherwise condensation on the tubers will occur which will promote rot.

Serenade Opti (Bacillus subtilis) can also be applied to potatoes entering storage for suppression of silver scurf.  See label for directions.

 

Potato Weed Management

Cultivation with a light harrow or finger weeder is the most effective way of controlling weeds prior to crop emergence. Use of this treatment just prior to crop emergence prolongs the period of effective pre or post emergent chemical weed control.

Numerous chemicals are available for weed control. Most treatments are applied by sprayer using low pressure (200 to 275 kPa) (30 to 40 psi) in 300 to 500 L/ha (120 to 200 L/acre) of water. See tables below.

Roundup as described in “Preplow Cleanup of Perennial Weeds” section of the Vegetable Production Guide: Pest Management (PDF, 1.2 MB).

Pre-plant : Herbicide Application Rates

Product Rate PHI* Comments

Eptam 8-E

(EPTC)

Group 8
4.25 to 8.5 L/ha
(1.7 to 3.4 L/acre)

Apply in 100 to 300 L/ha (40 to 120 L/acre) of water.
60
  • Controls most seedling grasses and many broadleaved weeds.
  • Do not use on muck soils.
  • Apply to moist soil and incorporate immediately to a depth of 5 to 7.5 cm. Cross- discing is recommended.
  • Planting may begin immediately following treatment.
  • The higher rate is necessary for quack grass control.

Eptam 8-E

(EPTC)

Group 8

PLUS:
 

Sencor 75 DF or                   

TriCor 75 DF or
Sencor Solu-Pak

(metribuzin)
(Interior BC)

Or

Sencor 75 DF or 

TriCor 75 DF or
Sencor Solu-Pak

(metribuzin)
(Coastal BC)

4.25 to 5.5 L/ha
(1.7 to 2.2 L/acre)

 

 

PLUS:

375 to 550** g/ha
(140 to 220 g/acre)


 

 

 

Or

0.75 to 1.1 kg/ha
(300 to 445 g/acre)

60
  • Do not use on the varieties Belleisle or Tobique.
  • Apply and immediately incorporate evenly into the top 5 to 7.5 cm.
  • Do not use on muck soils or soils with more than 7% organic matter.
  • Avoid rotations in the following year with crops sensitive to Sencor (i.e. onions, celery, peppers, cole crops, lettuce, spinach, table and sugar beets, turnips, cucurbits and rapeseed).
  • Do not use on red-skinned or early potatoes in sandy soils with less than 2% organic matter.
  • **In the Interior, can be used at up to 750 g/ha (304 g/acre) if application is made through irrigation system.
  • In the interior, Sencor products can now be used on the variety Shepody.
  • Do not apply on newly released varieties without proper consultation.
  • Apply in 200 to 300 L/ha (80 to 120 L/acre) of water.
  • Sencor: Group 5 herbicide.

Dual Magnum II

(s-metolachlor)

Group 15

PLUS:

Sencor 75 DF or                     TriCor 75 DF

(metribuzin)
(Coastal BC)

1.25 to 1.75 L/ha
(500 to 700 mL/acre)

 

 

 

PLUS:

0.75 to 1.5 kg/ha
(300 to 600 g/acre)

60
  • Do not use on the variety Superior.
  • Do not use on soils with more than 10% organic matter.
  • Controls nutsedge and most seedling grasses and some broadleaved weeds
  • Use the higher rate for heavier weed populations.
  • Do not use on sandy or course textured soils with les than 2% organic matter.
  • Do not apply on newly released varieties without proper consultation.
  • Do not enter treated area for 12 hours.
  • Apply in 150 to 300 L/ha (60 to 120 L/acre) of water.
  • Sencor: group 5 herbicide.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

Pre-emergence: Herbicide Application Rates

Product Rate PHI* Comments

Lorox L

(linuron)

Group 7
2.25 to 4.5 L/ha
(0.9 to 1.8 L/acre)

Apply in 300 L/ha (120 L/acre) of water.
N/A
  • Use the low rate on lighter soils (lower in clay or organic matter).  Use the high rate on heavier soils.
  • Do not use on coarse-textured soils, containing 2% or less organic matter, as crop injury may result.
  • Controls most annual grasses and chickweed, redroot pigweed, shepherd's purse and smartweed.
  • Will not control established perennial weeds or atrazine resistant weeds.
  • Make a single broadcast application after planting (at least 5 cm deep), but before the crop emerges.
  • Apply before broadleaf weeds are 15 cm tall and before grasses are 5 cm tall.
  • Treatment may be applied after hilling if potatoes are completely covered with soil.
  • Do not apply after potatoes have emerged.
  • Severe damage may result if pre-emergence application is followed by unusually heavy rains.
  • Do not replant to other crops within 4 months of application.
Sencor 75 DF or                   
Tricor 75 DF or                    
Sencor Solu-Pak
(metribuzin)
(Coastal BC)

0.55 to 1.5 kg/ha
(220 to 600 g/acres)
 

60
  • Pre-emergence treatment is recommended in coastal areas only.
  • Apply pre-emergence to weeds and crop immediately following last cultivation or hilling.
  • A light rain or irrigation following application will improve kill.
  • Will control a wide range of broadleaved weeds and grasses.
  • Does not control atrazine resistant weeds.
  • The higher rate is required for barnyard grass, green foxtail, and wild buckwheat and for suppression of Canada thistle, sowthistle and quackgrass.
  • Do not use on muck soils.
  • Use lower rate on coarse sandy soils.
  • Avoid rotation with crops sensitive to Sencor or Lexone the following year (e.g. onions, celery, peppers, cole crops, lettuce, and spinach). Residual injury has occurred on following crops of cereals in the Delta region in dry years. If high rates are used in dry years, plant potatoes for another year.
  • Do not use on the varieties Belleisle or Tobique (Warba or Shepody).
  • Do not apply on newly released varieties without proper consultation.
  • See label for rotational restrictions.
  • Do not enter treated area for 12 hours.

Dual Magnum II

(s-metolachlor)

Group 15

PLUS:

Sencor 75 DF or                   

TriCor 75 DF
(metribuzin)

 

1.25 to 1.75 L/ha
(500 to 700 mL/acre)
 

PLUS:

0.75 to 1.5 kg/ha
(300 to 600 g/acre)

60
  • Do not use on the variety Superior, Belleisle, Tobique.
  • Controls nutsedge and most seedling grasses and some broadleaved weeds.
  • Surface moisture is essential for good control.
  • Use the higher rate of Dual II Magnum for heavier weed problems.
  • Consult the appropriate labels for specific information on soil type variations and special restrictions for this tank-mixes.
  • Do not apply to soils with less than 2% organic matter.
  • Do not apply on newly released varieties without proper consultation.
  • Do not use Dual II Magnum at ground crack or if potatoes have emerged.
  • Do not enter treated area for 12 hours.
  • Sencor: group 5 herbicide.

Chateau

(flumioxazin)

Group 14

105 g/ha
(42 g/acre)
N/A
  • Suppresses redroot pigweed, lamb’s-quarters, hairy nightshade and black nightshade.
  • Apply prior to weed emergence.
  • Do not apply more than 105 g/ha (42 g/acre) during a growing season.
  • To avoid severe crop injury, do not apply after cracking.
  • May be applied after hilling.
  • At the time of application, a minimum of 5 cm (2 inches) of soil must cover the vegetative portion of the crop.
  • Use only on muck soils and medium textured mineral soils with <5% OM.
  • Applications made to poorly drained soils or under cool, wet conditions may result in crop injury.
  • Control may be improved by irrigation with at least ½ cm of water.

Outlook

(dimethenamid-P)

Group 15

Coarse textured soils: 

756 to 860 mL/ha (306 to 348 mL/acre)

Medium and fine-textured soils:

756 to 963 mL/ha (306 to 390 mL/acre)

Apply in 100 L/ha (40 L/acre) of water.

40

Coarse textured soils rate:

  • Use high rate for soils with high organic matter levels (7 to 10%).

Medium and fine-textured soils rate:

  • Use low rate for soils with low O.M. (<3%).
  • Use 860 mL/ha (348 mL/acre) for soils with medium O.M. (3 to 6%).
  • Use high rate for soils with high O.M. (7 to 10%).

All soils:

  • May only be applied in a single application.
  • Apply pre-emerge before weeds emerge and after potatoes have been planted.
  • Do not apply before planting or onto emerged potatoes.
  • Controls labeled broadleaf weeds and grasses such as barnyard grass.
  • Use the high rate of 963 mL/ha (390 mL/acre) to control Redroot pigweed and Eastern black nightshade.
  • Suppresses yellow nutsedge.
  • Do not exceed the specified rate by soil type in a single application.
  • Rainfall is required within 7 to 10 days of application to activate and move Outlook into the soil zone. 
  • A shallow cultivation may be necessary if dry conditions persist after applying.  Tillage should be minimal to minimize dilution of herbicide.
  • Delayed emergence or early season stunting of potatoes may result when applying Outlook in cold, wet conditions.
  • Do not graze or feed treated crop to livestock prior to 40 days after application.
  • See label for rotational crop and recropping restrictions.
  • Do not re-enter treated area for 24 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

Late Pre-emergence or Early Post-emergence: Herbicide Application Rates

Product Rate PHI* Comments
Sencor 75 DF or                   
TriCor 75 DF or                   
Sencor Solu-Pak
(metribuzin)
(Coastal BC)

Or

Sencor 75 DF or                   
TriCor 75 DF or                   
Sencor Solu-Pak
(metribuzin)
(Interior BC)

0.55 to 1.5 kg/ha
(0.3 to 0.6 kg/acre)

 

Or

375 g/ha
(150 g/acre)

90
  • Sensitive varieties that should not be treated early post-emergence include Warba, Red Pontiac, White Rose, Norgold Russet, Shepody, Belleisle, Tobique, Atlantic, Eramosa, red-skinned or early maturing varieties.
  • First use on a potato variety  should be limited to a small test area to ensure risk or level of potential injury is acceptable prior to field-wide use.
  • Apply before weeds are 4 cm and potatoes are less than 10 cm tall
  • Use the lower rate on coarse, sandy soil.
  • Tolerance will vary depending on soil type and stress conditions e.g. heat, drought, excessive rain or irrigation and cloudy weather followed by hot days.
  • Do not use this product on muck soils.
  • Note remarks about weed species and residue injury to rotation crops in pre-emergence section above.
  • Does not control atrazine resistant weeds.
  • Do not apply on newly released varieties without proper consultation.
  • Do not enter treated area for 12 hours.
  • Apply in 100 to 300 L/ha (40 to 120 L/acre).
  • Group 5 herbicide.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

Post-emergence: Herbicide Application Rates

Product Rate PHI* Comments

Poast Ultra

(sethoxydim)

Group 1

Annual grasses (incl. volunteer cereals):

320 mL/ha (130 mL/ac)

Annual grasses & quackgrass suppression:

470 mL/ha (190 mL/ac)

Quackgrass:

1.1 L/ha (445 mL/ac)
80
  • For control of annual grasses and quackgrass suppression, add Merge adjuvant using a rate of 0.5 - 1.0 L/ha (0.2 - 0.4 L/ac).
  • For control of quackgrass, add Merge adjuvant using a rate of 1.0 - 2.0 l/ha (0.4 - 0.8 L/ac).
  • Annual bluegrass is not controlled.
  • Apply when annual weeds are in the 1 to 6 leaf stage and when quackgrass is in the 1 to 3 leaf stage.
  • Apply in 50 to 200 L/ha (20 to 80 L/acre) of water at 240 kPa pressure..
  •  See label for water volume and pressure when weed infestations or crop canopies are dense.
  • Observe a 30 day plantback interval for crops not listed.
  • Do not enter treated area for 12 hours.

Venture L

(fluazifop-p-butyl)

Group 1

barnyard grass (2-5 leaf stage):
0.8 L/ha (0.32 L/acre)

proso millet (2-5 leaf):
1.0 L/ha (0.4 L/acre)

foxtails (2-4 leaf):
1.4 L/ha (0.56 L/acre)

quackgrass (3-5 leaf):
2.0 L/ha (0.8 L/acre)
45
  • Annual bluegrass and broadleaved weeds are not controlled.
  • May be tank-mixed with Sencor for early-post-emergent application.  Check label for details.
  • Apply in 50 to 200 L/ha (20 to 80 L/acre) water at 200 to 300 kPa.
  • Apply using 425 kPa pressure for dense weed infestations or dense crop canopies.
  • Warning: Women capable of bearing children should avoid exposure to Venture.
  • Do not handle more than 50 kg a.i. (400 L product) per day.
  • Use a closed cab when applying more than 33 kg a.i. (264 L product) per day.
  • Observe a plantback interval of 12 months for crops not listed.
  • Do not re-enter treated area for 12 hours.

Excel Super

(fenoxaprop-p-ethyl)

Group 1

670 mL/ha
(270 mL/acre)

Apply in at least 110 L/ha (45 L/acre) of water at 275 kPa.
35
  • Apply between the 1 to 6 leaf stage to control foxtails, crabgrass, barnyard grass, old witch grass, or Proso millet.
  • Does not control quackgrass, sedges, or other perennial grasses.
  • Do not apply any other pesticide or chemical 4 days before or after applying Excel Super.

Centurion /Select

(clethodim)

Group 1

Annual Grasses:
190 mL/ha
(77 mL/acre)

Quackgrass:
380 mL/ha
(150 mL/acre)
60
  • Apply when weeds are in 2 to 6 leaf stage.
  • Apply when quackgrass is 6 to 15 cm high.
  • Centurion/Select is to be used only with the adjuvant Amigo at 0.5 to 1.0% v/v.
  • Arrow 240 EC is to be used only with the adjuvant X-Act at 0.5 to 1.0 % v/v.
  • Allow 4 days between this application and any other chemical not found on the label.
  • Do not apply more than 380 mL/ha per season.
  • Do not enter treated area for 12 hours.
  • Apply in 55 to 225 L/ha (22 to 90 L/acre) of water.

Arrow 240 EC

(clethodim)

Group 1

Annual Grasses:
190 mL/ha
(77 mL/acre)

Quackgrass:

380 mL/ha(150 mL/acre)
60
  • Apply when weeds are in 2 to 6 leaf stage.
  • Apply when quackgrass is 6 to 15 cm high.
  • Centurion/Select is to be used only with the adjuvant Amigo at 0.5 to 1.0% v/v.
  • Arrow 240 EC is to be used only with the adjuvant X-Act at 0.5 to 1.0 % v/v.
  • Allow 4 days between this application and any other chemical not found on the label.
  • Do not apply more than 380 mL/ha per season.
  • Do not enter treated area for 12 hours.
  • Apply in 55 to 225 L/ha (22 to 90 L/acre) of water.

Prism 25 DF

(rimsulfuron)

Group 2

PLUS

Citowett Plus

Or

Agral 90

Or

Agsurf

60 g/ha
(24 g/acre)
 

 

PLUS

2.0 L/1000 L of spray solution

30
  • Apply to crop before flower initiation when annual grasses are 1 to 6 leaf, quackgrass is 3 to 6 leaf and redroot pigweed and lamb’s-quarters are 4 to 6 leaf.
  • Gives suppression of lamb’s quarter only.
  • Do not make more than 1 application per year.
  • Do not cultivate within 7 to 10 days prior to or after application
  • Apply when temperatures are between 5 to 28oC in the 24 hours before AND after application. Temperatures beyond this range or stress caused by other conditions increase potential for crop injury.
  • Not recommended for use on seed potatoes (leaves a mottled, virus-like effect on leaves for about two weeks).
  • For use on irrigated potatoes only
  • Dot not enter treated area for 12 hours.

Aim EC

(carfentrazone-ethyl)

Group 14

37 to 117 mL/ha
(15 to 47 mL/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Controls annual weeds.
  • Must be applied using hooded sprayers to weeds between the rows of the emerged crop.
  • Use an adjuvant such as Agral 90 or Agral-Surf at 0.25% v/v (0.25 L/100 L of spray solution) or Merge at 1% v/v (1 L/100 L of spray solution).
  • Precaution:  crop injury will occur when spray drift is allowed to come in contact with green stem tissue or leaves.
  • Apply only once per growing season.
  • Do not apply if used for vine-kill in the same season.  To use Aim EC as a harvest aid, see Vine-Killing section of this page.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

 

Potato Insect Management

 

Coastal Area and Seed Production Areas in the Interior

The green peach aphid, the potato aphid and the cotton aphid spread leaf roll and other viruses, and can cause physical damage to plants by feeding in large numbers. The green peach aphid is almond-shaped, usually yellow and is primarily found on the lower leaves. The potato aphid is similar in shape and colour, but is larger and is usually found on the upper leaves. The black cotton melon aphid, recently introduced from California, is similar in size to the green peach aphid, but resistant to most insecticides.

In past years, leaf roll outbreaks have been associated with infected seed sources and aphids arriving from overwintered host plants. The planting of certified virus-free seed has lowered the threat of leaf roll in recent years. This is generally true in table grade potatoes, but serious leaf roll problems can still develop rapidly if the cultural and chemical control practices listed below are not followed. In seed potatoes, seasonal aphid control is a requirement to ensure that adequate virus-free quality is maintained.

Cultural Control

The cultural procedures listed will prevent the build-up of leaf roll virus inoculum on farms. These practices will also reduce the threat of other common insect and disease problems.

  • Plant only B.C. certified seed potatoes if possible. Planting uncertified seed can lead to serious leaf roll problems.
  • Practice proper crop rotation and avoid planting potatoes in the same field in successive years.
  • Destroy all culls and volunteers from previous potato plantings.

Biological Control

Naturally occurring predators and parasites of aphids can often play a major role in suppressing aphid populations in table grade potatoes. Since fields must be monitored accurately and routinely to make proper use of these beneficial insects, interested growers are advised to contact a commercial monitoring service for advice.

Chemical Control

See table below. For potato seeds, initial protection can be obtained with application of a seed treatment as listed under the Potato Seed Piece Treatments section of this page.

Foliar spraying of seed potatoes for aphids should begin after mid-July. Table potatoes should be sprayed if aphid levels become noticeable. In the Lower Mainland, commercial monitoring services are available for tuber flea beetle and aphid populations.

Chemical Control of Aphids

Product Rate PHI* Comments

Neudosan

(potassium salt of fatty acids)
 
Used in organics
8.0 L/ha
(3.2 L/acre)
 
Apply in 700 to 1900 L/ha (280 to 770 L/acre) of water
0
  • Do not spray when plants are under stress.
  • Avoid spraying during full sun.
  • Also registered for control of spider mites.
  • Neudosan (PCP# 27886) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.

Bartlett Superior "70" Oil

(mineral oil)

10 L/ha
(4 L/acre)
 
Apply at a concentration of 1% (10 L of product/1000 L of water) per ha at 690 to 1380 kPa.
14
  • Will reduce the spread of aphid vectored PVY.
  • Thorough coverage is essential.
  • Repeat at a 7 day interval.
  • Maximum 10 applications per season.
  • Crop injury may occur if applied in direct sunlight or immediately prior to hot, sunny weather.
  • Apply in early morning or evening.
  • Do not apply another insecticide within 24 hours.
  • Carefully observe rate or crop injury may occur.
  • Do not apply prior to or during freezing weather or rain.
  • Do not enter treated area for 24 hours.

Superior "70" Oil

(mineral oil)
10 L/ha
(4 L/acre)
 
Apply at a concentration of 1% (10 L of product/1000 L of water) per ha at 690 to 1380 kPa.
14
  • Will reduce the spread of aphid vectored PVY.
  • Thorough coverage is essential.
  • Repeat at a 7 day interval.
  • Maximum 10 applications per season.
  • Crop injury may occur if applied in direct sunlight or immediately prior to hot, sunny weather.
  • Apply in early morning or evening.
  • Do not apply another insecticide within 24 hours.
  • Carefully observe rate or crop injury may occur.
  • Do not apply prior to or during freezing weather or rain.
  • Do not enter treated area for 24 hours.

Imidan 50-WP Instapak

(phosmet)
 
Group 1A
2.25 kg/ha
(910 g/acre)
7
  • Apply as required throughout the growing season.
  • Use sufficient water to provide good coverage.
  • Do not feed refuse to livestock.
  • Maximum 2 applications per season at least 7 days apart.
  • Use only every other year.
  • Do not enter treated area for 5 days.

Vydate L

(oxymyl)
 
Group 1A
2.3 to 3.0 L/ha
(0.9 to 1.2 L/acre)
 

Apply in 300 to 900 L/ha (120 to 365 L/acre) of water

7
  • Do not apply where run-off is likely to occur.
  • Do not spray when wind speeds exceed 10 km/h.
  • Use higher rate for severe infestations. 

Malathion 85E

(malathion)
 
Group 1B
735 to 1100 mL/ha
(295 to 445 mL/acre)
 
Apply in 1000 L/ha (405 L/acre) of water
3
  • Do not make more than 1 application per year.
  • Best control is obtained when temperature is above 20°C.
  • Toxic to fish.
  • Do not apply where runoff is likely to occur.
  • Do not apply after expiry date on the container label.
  • Do not re-enter treated area for 12 hours.

Orthene 75 SP

(acephate)
 
Group 1B
 
Do not use on potatoes destined for export to the U.S.A.
563 to 825 g/ha
(228 to 335 g/acre)
21
  • Do not apply more than 4 times per season.
  • Use the high rate only when heavy infestations are present.
  • Do not apply irrigation or if rainfall is expected within 48 hours of application.
  • Do not irrigate for at least 48 hours following application.
  • Do not enter treated area for 1 day. For activities involving significant foliar contact, gloves and cotton coveralls must be worn for 1 week.

Cygon 480/ Lagon 480 E

(dimethoate)
 
Group 1B

0.55 to 1.1 L/ha
(220 to 445 mL/acre)

7
  • Apply as a groundspray using a closed cab.
  • Use sufficient water for good coverage.
  • Repeat using a 7 day interval.
  • Will provide systemic protection as long as foliage is green.
  • Do not apply more than 2 times per season.
  • Toxic to bees. Avoid applying when the crop is in bloom.  If applications must be made during bloom, apply in the evening when most bees are not foraging.  
  • Do not re-enter treated area for 12 hours. 

Decis 5 EC

(deltamethrin)
 
Group 3
250 ml/ha
(100 ml/acre)
 
Apply in 300 to 400 L/ha (120 to 160 L/acre) of water
1
  • Will not control green peach aphid.
  • Do not apply more than 2 times per season.
  • Apply only once to muck soils before August 1st.

Concept

(imidacloprid & deltamethrin)
 
Group 3 & 4
650 mL/ ha
(265 mL/ ac)
 
Apply in 100 to 200 L/ha (40 to 80 L/acre) of water
7
  • Repeat at 5 day intervals as needed.
  • Do not apply more than 3 times per year.
  • Do not apply following a seed treatment or soil application of a Group 4 insecticide.
  • Observe a plant back interval of 9 months for peas and beans and one year for all other crops not listed on label.
  • Highly toxic to bees. Do not apply to blooming crops if bees are visiting treatment area.
  • Do enter treated area for 24 hours.

Assail 70 WP

(acetamiprid)
 
Group 4
56 to 86 g/ha
(23 to 35 g/acre)
 
Apply in 200 L/ha (80 L/acre) of water
7
  • Repeat using a 7 day interval.
  • Do not make more than 2 applications per year.
  • Do not apply more than 172 g/ha (70 g/acre) per season.
  • Toxic to bees.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Soil application:
7.5 to 12 mL per 100 m row
       
OR:

833 to 1333 mL/ha
(337 to 539 mL/acre)
 
 
N/A
  • Rates are based on 90 cm spacing.  See rate conversion chart of label for other row spacing.
  • Apply as a narrow band, in furrow directly to seed pieces / potatoes.
  • Do not follow with any subsequent application of a group 4 insecticide.
  • Do not apply more than 1 time per season as a soil application.

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Foliar application:
200 mL/ha
(80 mL/acre)
7
  • Repeat using a 7 day interval.
  • Do not make more than 2 applications per year.
  • Do not follow a soil or seed piece treatment application with a group 4 insecticide with a foliar application of Admire 240F or Alias 240 SC.
  • Do not re-enter treated area for 24 hours.

Actara 240SC

(thiamethoxam)
 
Group 4
In Furrow:

3.4 to 4.4 mL/100 m row  

 
OR
 
Based on 90 cm row spacing:

378 to 489 mL/ha
(153 to 198 mL /acre)
N/A
  • Apply as an in-furrow spray at planting.  
  • See label for acreage rate conversion chart.
  • Maximum of one application per season.
  • Do not apply to seed that has been treated with Actara 240SC.
  • Do not follow an in-furrow or soil application with a foliar spray of Actara 240SC or any other Group 4 or 4A insecticide in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • Toxic to bees.
  • See label for plant-back interval.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatments control table in this crop chapter.
  • Do not re-enter treated area for 12 hours.

Actara 240SC

(thiamethoxam)
 
Group 4
Foliar application:
109 mL/ha

(44 mL/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Do not apply if seed has been treated with Actara 240SC or any other group 4 or 4A insecticide.
  • Do not apply if Actara 240 SC has been applied in-furrow.
  • Repeat using a 7 to 10 day interval.
  • Do not make more than 2 foliar applications of thiamethoxam (either Actara 240SC or Actara 25WG)  per season.
  • Do not apply more than 218 mL/ha (88 mL/acre) per growing season.
  • Toxic to bees.  Do not apply to flowering crop or weeds.
  • Do not apply between 50% row closure and petal fall.
  • Do not make more than 1 application per year prior to 50% row closure.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatments section of this page.
  • Do not enter treated area for 12 hours.

Actara 25WG

(thiamethoxam)
 
Group 4
Foliar application:
105 g/ha

(42 g/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Apply to foliage before pests reach damaging levels.
  • Make a second application 7 to 10 days later if necessary.
  • Do not apply more than 210 g/ha (84 g/acre) of product per season.
  • Do not use if Actara 240SC or a Group 4 or 4A insecticide has been used in furrow in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • See Soil application comments for additional precautions PBI and re-entry.
  • Highly toxic to bees.  Do not apply or allow to drift onto blooming plants if bees are visiting the treated area.

Clutch 50 WDG

(clothianidin)
 
Group 4A
Foliar application:
70 to 105 g/ha
(28 to 42 g/acre)
14
  • Repeat applications using a  10 day interval.
  • A maximum of 3 applications may be made per crop per season.
  • Do not apply following a seed piece or in furrow application of a Group 4 or 4A insecticide.
  • Toxic to bees. Do not apply to flowering crops if bees are foraging.
  • Observe a one year plantback interval for leafy, root and tuber vegetables (except potato).
  • Do not enter treated areas for 12 hours.

Closer SC

(sulfloxaflor)
 
Group 4C
50 to 150 mL/ha
(20 to 60 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Do not make more than 2 applications per growing season.
  • Repeat at a 7 day interval.
  • Do not apply more than 300 mL/ha (120 mL/acre) per growing season.
  •  Observe a plantback interval of 30 days for crops not on this label. 
  • Do not enter treated area for 12 hours.

Twinguard

(sulfloxaflor & spinetoram)
 
Groups 4C & 5
200 g/ha
(80 g/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Do not make more than 2 applications per growing season.
  • Repeat at a 7 day interval.
  •  Do not enter treated area for 12 hours.

Sivanto Prime

(flupyradifurone)
 
Group 4D
500 to 750 mL/ha
(200 to 300 mL/acre)
 
Apply in at least 100 L/ha (40 L/acre) of water
7
  • Repeat at a 10 day interval.
  • Do not exceed a total of 2000 mL/ha (810 mL/acre) of product per season.
  • Toxic to bees.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Fulfill 50WG

(pymetrozine)
 
Group 9B
193 g/ha
(78 g/acre)
 
Apply in at least 100L/ha (40 L/acre) of water
14
  • Apply before populations build to damaging levels.
  • Affected aphids stop feeding shortly after exposure, but take up to 2 to 4 days to die.
  • Do not exceed 2 applications per crop per season.
  • Allow at least 7 days between applications.
  • Recommend product be used with a non-ionic adjuvant, see label for detail.
  • The plant back restriction is 30 days for all crops.
  • Do not enter treated area for 12 hours.
  • Do not spray when wind speed exceeds 15 km/h.

Beleaf 50SG

(flonicamid)
 
Group 9C
120 to 160 g/ha
(50 to 65 g/acre)
 
Apply in 94 L/ha (38L/acre) of water.
7
  • Repeat at 7 day intervals.
  • Do not apply more than 3 times per year.
  • Do not apply more than 480 g/ha (200 g/acre) of product per season.
  • Do not re-enter treated area for 12 hours.

Sefina

(afidopyropen)

Group 9D

200 mL/ha

(80 mL/acre)

Apply in 100 to 200 L/ha (40 to 80 L/acre) of water
7
  • Apply as a groundspray.
  • Do not use in the greenhouse.
  • Repeat using a 7 day interval.
  • Do not apply more than 4 times per year.
  • Ensure thorough coverage.
  • Do not apply more than 2.5 L/ha (1.0 L/acre) per year.
  • During the crop blooming period, apply only in the evening when most bees are not foraging.
  • Observe a plantback interval of 30 days for crops not listed.
  • Do not use for feed.
  • Do not re-enter for 12 hours.

Versys

(afidopyropen)

Group 9D

100 mL/ha

(40 mL/acre)

Apply in 100 L/ha (40 L/acre) of water
7
  • Repeat using a 7 day interval.
  • Do not apply more than 4 times per year.
  • Ensure thorough coverage.
  • Do not apply more than 1.25 L/ha (506 mL/acre) per year.
  • During the crop blooming period, apply only in the evening when most bees are not foraging.
  • Observe a plantback interval of 30 days for crops not listed.
  • Do not re-enter for 12 hours.

Movento

(spirotetramat)
 
Group 23
220 to 365 mL/ha
(90 to 150 mL/acre)
 
Apply in 300 L/ha (120 L/acre) of water
7
  • Repeat using a 7 day interval.
  • Maximum allowed per crop season: 730 mL/ha (295 mL/acre).
  • Do not enter treated area for 12 hours.
  • Movento 240 SC should be used with one of the following adjuvants: non-ionic (eg. Agral 90 or Ag-Surf) or methylated seed oil (eg. Hasten).
  • Toxic to bees.  Do not apply during crop flowering period or when flowering weeds are present.

Exirel

(cyantraniliprole)
 
Group 28
500 to 1500 mL/ha
(200 to 605 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Do not make more than 4 applications per growing season.
  • Repeat at 5 day intervals.
  • Do not apply more than 4.5 L/ha (1.8 L/acre) per season.
  • Use with an adjuvant such as Hasten NT at a rate of 0.25% v/v or MSO Concentrate with Leci-Tech at a rate of 0.5% v/v.
  • Do not apply for 60 days following a soil or seed treatment application of a group 28 insecticide. 
  • Toxic to bees and certain beneficial insects.  Do not apply when crop is blooming.  Apply early in the morning or late in the evening when bees are not active.
  • Note:  Do not tank-mix or apply in sequence with strobilurin-, copper- or captan-containing fungicides.
  •  Observe a plantback interval of 30 days for legume vegetables, crop group 1A (inlcuding beets, carrots, radish, parsnip, turnip) and crop group 2 (inlcuding beet greens and turnip greens). 
  • Observe a plantback interval of 1 year for crops not on this label.
  • Do not enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI-Canada = Organic Materials Review Institute of Canada.

Interior of B.C.

Beetles are yellow and black striped. Larvae are reddish orange, with two rows of black spots on each side. Eggs are laid in yellow clusters on the underside of leaves. This pest tends to develop resistance to insecticides. Rotation of products is essential.

Control

Treat when pest reaches economic levels with a product recommended in the table below. Young larvae are easier to kill than adults.

Chemical Control of Colorado Potato Beetles (CPB)

Product Rate PHI* Comments

Imidan 50-WP Instapak

(phosmet)
 
Group 1A
2.25 kg/ha
(900 g/acre)
7
  • Apply as required throughout the growing season.
  • Use sufficient water to provide good coverage.
  • Do not feed refuse to livestock.
  • Maximum 2 applications per season at least 7 days apart.
  • Use only every other year.
  • Do not enter treated area for 5 days.

Vydate L

(oxymyl)
 
Group 1A
2.3 to 3.0 L/ha
(0.9 to 1.2 L/acre)
 

Apply in 300 to 900 L/ha (120 to 365 L/acre) of water

7
  • Do not apply where run-off is likely to occur.
  • Do not spray when wind speeds exceed 10 km/h.
  • Use higher rate for severe infestations. 
  • Will not control CPB resistant to carbamates.

Concept

(imidacloprid & deltamethrin)
 
Group 3 & 4
650 mL/ ha
(265 mL/ ac)
 
Apply in 100 to 200 L/ha (40 to 80 L/acre) of water
7
  • Repeat at 5 day intervals as needed.
  • Do not apply more than 3 times per year.
  • Do not apply following a seed treatment or soil application of a Group 4 insecticide.
  • Observe a plant back interval of 9 months for peas and beans and one year for all other crops not listed on label.
  • Highly toxic to bees. Do not apply to blooming crops if bees are visiting treatment area.
  • Do enter treated area for 24 hours.

Titan ST

(clothianidin)

Group 4

In-furrow:

2.0 to 3.33 mL per 100 m row

(221 to 373 mL/ha based on 90 cm row spacing)
N/A
  • Apply as a narrow band in-furrow, directing spray on the seed pieces.
  • Do not apply more than once per season as a soil application.
  • Do not make any subsequent applications of a Group 4 insecticide such as a foliar treatment.
  • Do not apply in conjunction with a group 4 insecticide seed piece treatment.
  • Do not re-enter treated area for 12 hours.

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Soil application:
7.5 to 12 mL per 100 m row
       
OR:

833 to 1333 mL/ha
(337 to 539 mL/acre)

 

 

N/A

  • Rates are based on 90 cm spacing.  See rate conversion chart of label for other row spacing.
  • Apply as a narrow band, in furrow directly to seed pieces / potatoes.
  • Do not follow with any subsequent application of a group 4 insecticide.
  • Do not apply more than 1 time per season as a soil application.

 

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Foliar application:
200 mL/ha
(80 mL/acre)
7
  • Repeat using a 7 day interval.
  • Do not make more than 2 applications per year.
  • Do not follow a soil or seed piece treatment application with a group 4 insecticide with a foliar application of Admire240F or Alias 240 SC.
  • Do not re-enter treated area for 24 hours.

Malathion 85E

(malathion)
 
Group 1B
735 to 1100 mL/ha
(295 to 445 mL/acre)
 
Apply in 1000 L/ha (405 L/acre) of water
3
  • Do not make more than 1 application per year.
  • Best control is obtained when temperature is above 20°C.
  • Toxic to fish.
  • Do not apply where runoff is likely to occur.
  • Do not apply after expiry date on the container label.
  • Do not re-enter treated area for 12 hours.

Actara 240SC

(thiamethoxam)
 
Group 4
Soil application:

3.4 to 4.4 mL/100 m row       

OR:
 
Based on 90cm row spacing:

378 to 489 mL/ha
(153 to 198 mL /acre)
 
 

N/A

 

 

 

  • Apply as an in-furrow spray at planting.
  • See label for acreage rate conversion chart.
  • Maximum of one application per season.
  • Do not apply to seed that has been treated with Actara 240SC.
  • Do not follow a soil application with a foliar spray of Actara 240SC or any other Group 4 or 4A insecticide in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • Toxic to bees.
  • See label for plant-back interval.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatments section of this page.
  • Do not re-enter treated area for 12 hours.

Actara 240SC

(thiamethoxam)
 
Group 4
Foliar application:
109 mL/ha

(44 mL/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Do not apply if seed has been treated with Actara 240SC or any other group 4 or 4A insecticide.
  • Do not apply if Actara 240 SC has been applied in-furrow.
  • Repeat using a 7 to 10 day interval.
  • Do not make more than 2 foliar applications of thiamethoxam (either Actara 240SC or Actara 25WG)  per season.
  • Do not apply more than 218 mL/ha (88 mL/acre) per growing season.
  • Toxic to bees.  Do not apply to flowering crop or weeds.
  • Do not apply between 50% row closure and petal fall.  
  • Do not make more than 1 application per year prior to 50% row closure.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatment section of this page.
  • Do not re-enter treated area for 12 hours.

Actara 25WG

(thiamethoxam)
 
Group 4
Foliar application:
105 g/ha

(42 g/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Apply to foliage before pests reach damaging levels.
  • Make a second application 7 to 10 days later if necessary.
  • Do not apply more than 210 g/ha (84 g/acre) of product per season.
  • Do not use if Actara 240SC or a Group 4 or 4A insecticide has been used in furrow in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • See Soil application comments for additional precautions PBI and re-entry.
  • Highly toxic to bees.  Do not apply or allow to drift onto blooming plants if bees are visiting the treated area.

Clutch 50 WDG

(clothianidin)
 
Group 4A
Soil application:  
2.38 to 4.0 g/100 m of row
 
OR:
 
Based on 90 cm row spacing:

266 to 448 g/ha
(108 to 181 g/acre)
 
 
N/A
  • Apply as a narrow band, in-furrow at planting, directing the spray on the seed pieces.
  • Do not make more than 1 application per season.
  • Do not follow a soil application with a foliar application of a Group 4 or 4A Insecticide.
  • Do not use in areas treated with clothianidin during the previous season.
  • Toxic to bees. Do not apply to flowering crops if bees are foraging.
  • Observe a one year plantback interval for leafy, root and tuber vegetables (except potato).
  • Do not enter treated areas for 12 hours.

Clutch 50 WDG

(clothianidin)
 
Group 4A
Foliar application:
70 to 105 g/ha
(28 to 42 g/acre)
14
  • Repeat applications at 10 intervals.
  • A maximum of 3 applications may be made per crop per season.
  • Do not apply following a seed piece or in furrow application of a Group 4 or 4A insecticide.
  • Toxic to bees. Do not apply to flowering crops if bees are foraging.
  • Observe a one year plantback interval for leafy, root and tuber vegetables (except potato).
  • Do not enter treated areas for 12 hours.

Assail 70 WP

(acetamiprid)
 
Group 4
40 to 80 g/ha
(16 to 32 g/acre)
 
Apply in 200 L/ha (80 L/acre) of water
7
  • Use higher rate when majority of the CPB population is in the adult stage.
  • Repeat at a 7 day interval.
  • Do not make more than 2 applications per year.
  • Do not apply more than 172 g/ha (70 g/acre) per season.
  • Toxic to bees.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Twinguard

(sulfloxaflor & spinetoram)
 
Groups 4C & 5
200 to 300 g/ha
(80 to 120 g/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Time applications for egg hatch or small larvae.
  • Repeat at 7 to 14 day intervals.
  • Do not make more than 2 applications per year.
  • Toxic to bees exposed to direct treatment, drift or residues.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Sivanto Prime

(flupyradifurone)
 
Group 4D
750 to 1000 mL/ha
(300 to 400 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Repeat at a 10 day interval.
  • Do not exceed a total of 2000 mL/ha (810 mL/acre) of product per season.
  • Toxic to bees.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Entrust 80

(spinosad)
 
Group 5 
 
Used in organics
50 to 100 g/ha
(20 to 40 g/acre)
7
  • Target eggs at hatch or small larvae.
  • Repeat using a 7 to 10 day interval.
  • Do not apply more than two times per year.
  • Do not apply more than 150 g/ha (60 g/acre) per year.
  • Highly toxic to bees.  Do not apply if bees are visiting the area.  
  • Harmful to parasitoids and predatory mites.  Slightly harmful to foliage-dwelling predators.
  • Do not enter treated areas for 12 hours.
  • Entrust products are OMRI-USA listed.  Check with your certification body before using in an organic operation.
  • Do not re-enter treated area for 12 hours.

Entrust

(spinosad)
 
Group 5 
 
 Used in organics
167 to 334 mL/ha
(68  to 135 mL/acre)
7
  • Target eggs at hatch or small larvae.
  • Repeat using a 7 to 10 day interval.
  • Do not apply more than two times per year.
  • Do not apply more than 500 mL/ha (202 mL/acre) per year.
  • Highly toxic to bees.  Do not apply if bees are visiting the area.  
  • Harmful to parasitoids and predatory mites.  Slightly harmful to foliage-dwelling predators.
  • Entrust products are OMRI-USA listed.  Check with your certification body before using in an organic operation.
  • Do not re-enter treated areas for 12 hours.

Success

(spinosad)
 
Group 5
83 to 167 ml/ha
(34 to 68 ml/acre)
7
  • Target eggs at hatch or small larvae.
  • Repeat using a 7 to 10 day interval.
  • Do not apply more than two times per year.
  • Do not apply more than 250 ml product/ha (101 ml/acre) per year.
  • Highly toxic to bees.  Do not apply if bees are visiting the area.  
  • Harmful to parasitoids and predatory mites.  Slightly harmful to foliage-dwelling predators.
  • Do not re-enter treated areas for 12 hours.

Delegate

(spinetoram)
 
Group 5
160 to 240 g/ha
(65 to 98 g/acre)
7
  • Time applications for egg hatch or small larvae.
  • Repeat at 7 to 14 day intervals.
  • Do not make more than 3 applications per year.
  • Toxic to bees exposed to direct treatment, drift or residues.  Do not apply to flowering crops or weeds if bees are visiting the treatment area.
  • Do not enter treated areas for 12 hours.

Minecto Pro

(abamectin/ cyantraniliprole)

 

Group 6 & 28

556 to 670 mL/ha

(225 to 270 mL/acre)

 

Apply in 200 L/ha (80 L/acre) of water
14
  • Use with 0.1 to 0.5% v/v non-ionic surfactant in the spray mixture.
  • Make the 1st application after approximately 50% of the egg masses have hatched and larvae are present.
  • Ensure thorough coverage.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season using the high rate.
  • Do not apply more than 3 times per season using the low rate.
  • Do not apply more than 1.340 L/ha (540 mL/acre) per season.
  • Do not apply if any group 28 insecticide was used at planting as an in-furrow, soil or seed-piece treatment.
  • Check label for plantback intervals.
  • Do not re-enter for 12 hours.

Rimon 10 EC

(novaluron)
 
Group 15
410 to 820 mL/ha
(165 to 330 mL/acre)

Apply in 100 L/ha (40 L/acre) of water
14
  • Apply when the majority of the CPB population is at egg hatch to the 2nd instar.
  • Repeat at 10 to 14 day intervals.
  • Do not apply more than 2 times per season.
  • Do not apply more than 1640 mL/ha (660 mL/acre) per season.
  • Do not enter treated area for 12 hours.

Coragen

(chlorantraniliprole)
 
Group 28
250 to 500 mL/ha
(100 to 150 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
1
  • Repeat at 3 day intervals.
  • Do not make more than 4 applications per season.
  • Do not enter treated area for 12 hours.

Verimark

(cyantraniliprole)

Group 28

In-furrow:
6.75 to 9 mL per 100 m of row
 
OR:
 
Based on 90 cm row spacing:
750 to 1000 mL/ha 
(305 to 405 mL/acre)
N/A
  • Apply as a narrow band, directing the spray on the seed pieces in the furrow.
  • Adjust the pH of the spray tank to approximately 4 to 6 using a commercially available acidifier.  See label for directions.
  • Do not make more than 1 soil or seed-piece application per season.
  • Do not follow with a subsequent foliar application of a group 28 insecticide after treating with Verimark in-furrow or as a seed-treatment.
  • Do not apply more than 1.5 L/ha (0.6 L/acre) per season.
  • Observe a plantback interval of 30 days for legume vegetables, cereals, grass, crop group 1A (inlcuding beets, carrots, radish, parsnip, turnip) and crop group 2 (inlcuding beet greens and turnip greens). 
  • Observe a plantback interval of 1 year for crops not on this label.
  • Also allowed as a seed-piece treatment.  See Potatoes Seed Piece Treatments control table for details.

Exirel

(cyantraniliprole)
 
Group 28
750 to 1000 mL/ha
(305 to 405 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Do not make more than 4 applications per growing season.
  • Repeat at 7 to 14 day intervals.
  • Do not apply more than 4.5 L/ha (1.8 L/acre) per season.
  • Do not apply following a soil or seed treatment application of a group 28 insecticide. 
  • Toxic to bees and certain beneficial insects.  Do not apply when crop is blooming.  Apply early in the morning or late in the evening when bees are not active.
  • Note:  Do not tank-mix or apply in sequence with strobilurin-, copper- or captan-containing fungicides.
  •  Observe a plantback interval of 30 days for legume vegetables, cereals, grass, crop group 1A (inlcuding beets, carrots, radish, parsnip, turnip) and crop group 2 (inlcuding beet greens and turnip greens). 
  • Observe a plantback interval of 1 year for crops not on this label.
  • Do not enter treated area for 12 hours.

Sevin XLR

(carbaryl)
 
Group 1A
1.25 L/ha
(500 mL/acre)
7
  • Maximum of 2 applications per year.
  • Repeat using a 7 day interval.
  • It is recommended that the level of resistance of local CPB be established by using a diptest early in the season, before spraying.
  • Toxic to bees.  Avoid applying during the crop blooming period.  If necessary to treat, apply in the evening to avoid foraging bees.
  • Do not enter treated areas for irrigation activities for 6 days.  Do not re-enter for scouting for 12 hours.

Dibrom

(naled)
 
Group 1B
1.1 L/ha
(450 mL/acre)
 
Apply in 100 to 300 L/ha (40 to 120 L/acre) of water
4
  • Application during hot weather may result in crop injury.
  • Do not apply in temperatures above 32°C.
  • Maximum 2 applications per season.
  • Do not enter treated area for 48 hours.

Decis 5 EC

(deltamethrin)
 
Group 3
100 to150 mL/ha
(40 to 60 mL/acre)
 
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
1
  • Do not use more than 3 times per season.
  • For tuber flea beetle, use 150 to 200 mL/ha (60 to 80 mL/acre).
  • Will kill beneficials.
  • Repeated use may result in severe reductions of beneficial arthropods.
  • Apply only once to muck soils, before August 1st.

Matador 120EC/ Silencer 120EC

(lambda-cyhalothrin)
 
Group 3
 
83 to 125 mL/ha (34 to 51 mL/acre)
7
  • Allow a 7 day interval between treatments.
  • Use the high rate when CPB larvae are beyond the 2nd instar stage or when populations are high.
  • Do not apply more than 250 mL/ha (100 mL/acre) of product per season.
  • Toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 24 hours.

Pounce EC

(permethrin)
180 to 260 mL/ha
(70 to 105 mL/acre)
1
  • Use the higher rate for heavy infestations.
  • Repeat as necessary.
  • Use sufficient water for complete coverage.
  • Very toxic to bees. Avoid spraying when bees are foraging.

Perm-Up EC

(permethrin)
 
Group 3
180 to 260 mL/ha
(70 to 105 mL/acre)
1
  • Use the higher rate for heavy infestations.
  • Repeat as necessary.
  • Use sufficient water for complete coverage.
  • Very toxic to bees. Avoid spraying when bees are foraging.

Mako

(cypermethrin)
 
Group 3
62.5 to 125 mL/ha
(26 to 51 mL/acre)
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 2 times per year.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Up-Cyde 2.5 EC

(cypermethrin)
 
Group 3
140 mL per ha
(55 mL per acre)
  
Apply in 100 to 500 L/ha (40 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 3 times per year.
  • Do not apply more than 3 times per season.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Pyrinex 480 EC

(chloropyrifos)
 
Group 1B
1.0 L/ha
(400 mL/acre)
7
  • Apply in 400 to 800 L/ha (160 to 325 L/acre) of water.
  • Do not make more than once per season.
  • Do not use on crops for export to the USA.
  • Do not enter treated area for 24 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI-USA = Organic Materials Review Institute of USA.

Small, black, fast-jumping beetles eat holes in leaves causing a shot-hole appearance. Larvae feed by tunneling just beneath the skin of the tubers. Heavy feeding in a tuber produces a network of fine tunnels that cause cracks and pimples on the surface; which, later, may resemble common scab.

Control efforts should concentrate on achieving complete control of the flea beetles as they first enter the crop in May and June. This will reduce the need to routinely spray for this pest later in the growing season.

Monitoring

Beginning on May 15, sample all emerged fields or volunteers for tuber flea beetles. Fields should be sampled even if only 25% of the crop has emerged. When plants are small, visual observations to detect beetles or damage to the foliage should be made at regular 7-day intervals. Observe 10 samples of 10 consecutive plants each per hectare; i.e. 100 plants.

Treat immediately as outlined below if there is an average of more than one beetle or feeding hole per sample of 10 plants.

Later, when the foliage is about 15 cm high, assess the flea beetle population by sweeping with a 35 cm net at 7-day intervals throughout the growing season. Twenty-five samples of 10 net sweeps each (i.e. 250 sweeps) is adequate for fields of 4 ha (10 acres) or larger, providing the samples are taken around the outside 4 rows as well as diagonally from corner to corner in two directions. Net sweeping is reliable only under conditions of low wind, bright sunlight and temperatures over 21°C. Treat immediately as outlined below if there is an average of more than one beetle per sample of 10 net sweeps.

Beetles migrate from one field to another so net sweeping is more effective if done on an area wide basis.

In the Lower Mainland, commercial monitoring services for tuber flea beetle and aphid populations are available. Late blight monitoring is also a part of the insect monitoring program. 

Cultural Control

Follow the cultural control methods described for aphids above.

Flea beetles first invade potato fields along the outer rows. Planting the outer rows of potatoes to parallel all sides of the field will enable more effective edge treatments. The number of outer rows should equal the number of rows covered by a sprayer swath.

Fields must be rotated to avoid subsequent infestations inside the field, leading to many more sprays per crop.

Chemical Control

The proper choice of insecticide is important in controlling the first beetles. In May and June, synthetic pyrethroids such as Pounce or Ripcord should be used. These products are very toxic to flea beetles and last almost twice as long as the other products listed. They also work well in cooler temperatures. It is best to avoid using these insecticides later in the season, if possible, as they have low toxicity to aphids, but are toxic to beneficial insects.

For good control, upper and lower surfaces of leaves must be covered with the insecticide. Use a drop-pendant sprayer and vine-lifters. Apply sprays in 800 to 1000 L/ha (300 to 400 L/acre) of water.

Early Crop

Treat when beetle or damage is observed on the leaves or on June 1 to 7, whichever is first.

Mid and Later Season Crops

Begin treatments when plants are 5 cm high.
See table below.

Chemical Control of Flea Beetles

Product Rate PHI* Comments

Imidan 50-WP Instapak

(phosmet)
 
Group 1A
2.25 kg/ha
(900 g/acre)
7
  • Apply as required throughout the growing season.
  • Use sufficient water to provide good coverage.
  • Do not feed refuse to livestock.
  • Maximum 2 applications per season at least 7 days apart.
  • Use only every other year.
  • Do not enter treated area for 5 days.

Vydate L

(oxymyl)
 
Group 1A
2.3 to 3.0 L/ha
(0.9 to 1.2 L/acre)
 

Apply in 300 to 900 L/ha (120 to 365 L/acre) of water

7
  • Do not apply where run-off is likely to occur.
  • Do not spray when wind speeds exceed 10 km/h.
  • Use higher rate for severe infestations or if aphids are primary pest. 

Concept

(imidacloprid & deltamethrin)
 
Group 3 & 4
650 mL/ ha
(265 mL/ ac)
 
Apply in 100 to 200 L/ha (40 to 80 L/acre) of water
7
  • Repeat at 5 day intervals as needed.
  • Do not apply more than 3 times per year.
  • Do not apply following a seed treatment or soil application of a Group 4 insecticide.
  • Observe a plant back interval of 9 months for peas and beans and one year for all other crops not listed on label.
  • Highly toxic to bees. Do not apply to blooming crops if bees are visiting treatment area.
  • Do enter treated area for 24 hours.

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Soil application:
7.5 to 12 mL per 100 m row
       
OR:

833 to 1333 mL/ha
(337 to 539 mL/acre)

N/A

  • Rates are based on 90 cm spacing.  See rate conversion chart of label for other row spacing.
  • Apply as a narrow band, in furrow directly to seed pieces / potatoes.
  • Do not follow with any subsequent application of a group 4 insecticide.
  • Do not apply more than 1 time per season as a soil application.

 

 

 

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Foliar application:
200 mL/ha
(80 mL/acre)
7
  • Repeat using a 7 day interval.
  • Do not make more than 2 applications per year.
  • Do not follow a soil or seed piece treatment application with a group 4 insecticide with a foliar application.
  • The foliar application is for aphid and CPB control only.
  • Do not re-enter treated area for 24 hours.

Orthene 75 SP

(acephate)
 
Group 1B
 
Do not use on potatoes destined for export to the U.S.A.
563 to 825 g/ha
(228 to 335 g/acre)
21
  • Do not apply more than 4 times per season.
  • Use the high rate only when heavy infestations are present.
  • Do not apply irrigation or if rainfall is expected within 48 hours of application.
  • Do not irrigate for at least 48 hours following application.
  • Do not enter treated area for 1 day. For activities involving significant foliar contact, gloves and cotton coveralls must be worn for 1 week.

Sevin XLR

(carbaryl)
 
Group 1A
2.5 L/ha
(1.0 L/acre)
7
  • Maximum of 2 applications per year.
  • Repeat using a 7 day interval.
  • Toxic to bees.  Avoid applying during the crop blooming period.  If necessary to treat, apply in the evening to avoid foraging bees.
  • Do not enter treated areas for irrigation activities for 6 days.  Do not re-enter for scouting for 12 hours.

Dibrom

(naled)
 
Group 1B
1.1 L/ha
(450 mL/acre)
 
Apply in 100 to 300 L/ha (40 to 120 L/acre) of water
4
  • Application during hot weather may result in crop injury.
  • Do not apply in temperatures above 32°C.
  • Maximum 2 applications per season.
  • Do not enter treated area for 48 hours.

Decis 5 EC

(deltamethrin)
 
Group 3
100 to 200 mL/ha
(60 to 80 mL/acre)
 
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
1
  • Do not use more than 3 times per season.
  • Will kill beneficials.
  • Repeated use may result in severe reductions of beneficial arthropods.
  • Apply only once to muck soils, before August 1st.

Matador 120EC/ Silencer 120EC

(lambda-cyhalothrin)
 
Group 3
83 mL/ha
(34 mL/acre)
7
  • Allow a 7 day interval between treatments.
  • Do not apply more than 250 mL/ha (100 mL/acre) of product per season.
  • Toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 24 hours.

Pounce EC

(permethrin)
180 to 260 mL/ha
(70 to 105 mL/acre)
1
  • Use the higher rate for heavy infestations.
  • Repeat as necessary.
  • Use sufficient water for complete coverage.
  • Very toxic to bees. Avoid spraying when bees are foraging.

Perm-Up EC

(permethrin)
 
Group 3
180 to 260 mL/ha
(70 to 105 mL/acre)
1
  • Use the higher rate for heavy infestations.
  • Repeat as necessary.
  • Use sufficient water for complete coverage.
  • Very toxic to bees. Avoid spraying when bees are foraging.

Mako

(cypermethrin)
 
Group 3

 

62.5 to 125 mL/ha
(26 to 51 mL/acre)
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 2 times per year.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Up-Cyde 2.5 EC

(cypermethrin)
 
Group 3
140 mL per ha
(55 mL per acre)
 
Apply in 100 to 500 L/ha (40 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 3 times per season.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Pyrinex 480 EC

(chloropyrifos)
 
Group 1B
1.0 L/ha
(400 mL/acre)
 
Apply in 400 to 800 L/ha (160 to 325 L/acre) of water
7
  • Do not make more than once per season.
  • Do not use on crops for export to the USA.
  • Do not enter treated area for 24 hours.

Entrust SC

(spinosad)
 
Group 5 
 
Used in organics
334 mL/ha
(135 mL/acre)
7
  • Suppression only.
  • Apply when 1 adult is seen per field edge for crawling samples (overwintering), or when 8 are seen per edge for sweep net samples (2nd and 3rd generation) .
  • Do not apply more than 500 mL/ha (202 mL/acre) per year.
  • Harmful to beneficials.
  • Do not enter treated areas for 12 hours.
  • Entrust products are OMRI-USA listed.  Check with your certification body before using in an organic operation.

Minecto Pro

(abamectin/ cyantraniliprole)

 

Group 6 & 28

370 to 670 mL/ha

(150 to 270 mL/acre)

Apply in 200 L/ha (80 L/acre) of water
14
  • Use with 0.1 to 0.5% v/v non-ionic surfactant in the spray mixture.
  • Ensure thorough coverage.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season using the high rate.
  • Do not apply more than 3 times per season using the low rate.
  • Do not apply more than 1.340 L/ha (540 mL/acre) per season.
  • Do not apply for 60 days following an in-furrow or soil application or seed piece treatment with any group 28 insecticide.
  • Check label for plantback intervals.
  • Do not re-enter for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI-USA = Organic Materials Review Institute of USA.

Leafhoppers are small, flying insects, gray, green or brown in colour and measure up to 5 mm. They are present in great numbers in grassy and bushy field borders in July and August and invade potato fields. They are sucking insects and some species transmit the diseases Aster Yellows and Witches’ Broom. See “Disease Control”, this section.

Control

See table below. Sprays should be applied when potato plants are 10 cm high, if leafhoppers are present.

Where possible, spray areas 9 to 15 m wide surrounding the field; this kills the leafhoppers before they get to the potato field. Leafhoppers move into potato fields when surrounding vegetation begins to dry up.

Chemical Control of Leafhoppers

Product Rate PHI* Comments

Imidan 50-WP Instapak

(phosmet)
 
Group 1A
2.25 kg/ha
(900 g/acre)
7
  • Apply as required throughout the growing season.
  • Use sufficient water to provide good coverage.
  • Do not feed refuse to livestock.
  • Maximum 2 applications per season at least 7 days apart.
  • Use only every other year.
  • Do not enter treated area for 5 days.

Vydate L

(oxymyl)
 
Group 1A
2.3 to 3.0 L/ha
(0.9 to 1.2 L/acre)
 

Apply in 300 to 900 L/ha (120 to 365 L/acre) of water

7
  • Do not apply where run-off is likely to occur.
  • Do not spray when wind speeds exceed 10 km/h.
  • Use higher rate for severe infestations or if aphids are primary pest.

Concept

(imidacloprid & deltamethrin)
 
Group 3 & 4
650 mL/ ha
(265 mL/ ac)
 
Apply in 100 to 200 L/ha (40 to 80 L/acre) of water
7
  • Repeat at 5 day intervals as needed.
  • Do not apply more than 3 times per year.
  • Do not apply following a seed treatment or soil application of a Group 4 insecticide.
  • Observe a plant back interval of 9 months for peas and beans and one year for all other crops not listed on label.
  • Highly toxic to bees. Do not apply to blooming crops if bees are visiting treatment area.
  • Do enter treated area for 24 hours.

Titan ST

(clothianidin)

Group 4

In-furrow:

2.0 to 3.33 mL per 100 m row

(221 to 373 mL/ha based on 90 cm row spacing)
N/A
  • Apply as a narrow band in-furrow, directing spray on the seed pieces.
  • Do not apply more than once per season as a soil application.
  • Do not make any subsequent applications of a Group 4 insecticide such as a foliar treatment.
  • Do not apply in conjunction with a group 4 insecticide seed piece treatment.
  • Do not re-enter treated area for 12 hours.

Admire 240F/ Alias 240 SC

(imidacloprid)
 
Group 4
Soil application:
7.5 to 12 mL per 100 m row
       
OR:

833 to 1333 mL/ha
(337 to 539 mL/acre)

 

N/A

  • Suppression only.
  • Rates are based on 90 cm spacing.  See rate conversion chart of label for other row spacing.
  • Apply as a narrow band, in furrow directly to seed pieces / potatoes.
  • Do not follow with any subsequent application of a group 4 insecticide.
  • Do not apply more than 1 time per season as a soil application.

Malathion 85E

(malathion)
 
Group 1B
735 to 1100 mL/ha
(295 to 445 mL/acre)
 
Apply in 1000 L/ha (405 L/acre) of water
3
  • Do not make more than 1 application per year.
  • Best control is obtained when temperature is above 20°C.
  • Toxic to fish.
  • Do not apply where runoff is likely to occur.
  • Do not apply after expiry date on the container label.
  • Do not re-enter treated area for 12 hours.

Actara 240SC

(thiamethoxam)
 
Group 4
Soil application:

3.4 to 4.4 mL/100 m row       

 
OR:
 
Based on 90cm row spacing:

378 to 489 mL/ha
(153 to 198 mL /acre)

 

N/A

 

 

 

 

  • Apply as an in-furrow spray at planting.
  • See label for acreage rate conversion chart.
  • Maximum of one application per season.
  • Do not apply to seed that has been treated with Actara 240SC.
  • Do not follow a soil application with a foliar spray of a Group 4 or 4A insecticide in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • Toxic to bees.  
  • See label for plant-back interval.
  • Do not re-enter treated area for 12 hours.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatments section of this page.
  • Do not re-enter treated area for 12 hours.

Actara 240SC

(thiamethoxam)
 
Group 4

Foliar application:

109 mL/ha

(44 mL/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Do not apply if seed has been treated with a group 4 or 4A insecticide.
  • Do not apply if Actara 240 SC has been applied in-furrow.
  • Repeat using a 7 to 10 day interval.
  • Do not make more than 2 foliar applications of thiamethoxam (either Actara 240SC or Actara 25WG)  per season.
  • Do not apply more than 218 mL/ha (88 mL/acre) per growing season.
  • Toxic to bees.  Do not apply to flowering crop or weeds.
  • Do not apply between 50% row closure and petal fall.  
  • Do not make more than 1 application per year prior to 50% row closure.
  • Can also be used as a seed treatment.  See Potatoes Seed Piece Treatment section of this page.
  • Do not re-enter treated area for 12 hours.

Actara 25WG

(thiamethoxam)
 
Group 4
Foliar application:
105 g/ha

(42 g/acre)

Apply in 100 L/ha (40 L/acre) of water

7
  • Apply to foliage before pests reach damaging levels.
  • Make a second application 7 to 10 days later if necessary.
  • Do not apply more than 210 g/ha (84 g/acre) of product per season.
  • Do not use if a Group 4 or 4A insecticide has been used in furrow in the same season.
  • If a cover crop is planted after potatoes are harvested, do not feed to livestock or harvest for food.
  • Highly toxic to bees.  Do not apply or allow to drift onto blooming plants if bees are visiting the treated area.
  • Do not enter treated area for 12 hours.

Clutch 50 WDG

(clothianidin)
 
Group 4A
 

 

Foliar application:

70 to 105 g/ha

(28 to 42 g/acre)

14

 

  • Repeat applications using a 10 day interval.
  • A maximum of 3 applications may be made per crop per season.
  • Do not apply following a seed piece or in furrow application of a Group 4 or 4A insecticide.
  • Toxic to bees. Do not apply to flowering crops if bees are foraging.
  • Observe a one year plantback interval for leafy, root and tuber vegetables (except potato).
  • Do not enter treated areas for 12 hours.

Orthene 75 SP

(acephate)
 
Group 1B
 
Do not use on potatoes destined for export to the U.S.A.
563 to 825 g/ha
(228 to 335 g/acre)
21
  • Do not apply more than 4 times per season.
  • Use the high rate only when heavy infestations are present.
  • Do not apply irrigation or if rainfall is expected within 48 hours of application.
  • Do not irrigate for at least 48 hours following application.
  • Do not enter treated area for 1 day. For activities involving significant foliar contact, gloves and cotton coveralls must be worn for 1 week.

Lagon 480 E

(dimethoate)
 
Group 1B

0.55 to 1.1 L/ha
(200 to 450 mL/acre)

Apply in 200 to 300 L/ha (80 to 120 L/acre) of water

7
  • Will provide systemic protection as long as foliage is green.
  • Do not apply more than 3 times per season.

Sevin XLR

(carbaryl)
 
Group 1A
2.5 L/ha
(1.0 L/acre)
7
  • Maximum of 2 applications per year.
  • Repeat using a 7 day interval.
  • Toxic to bees.  Avoid applying during the crop blooming period.  If necessary to treat, apply in the evening to avoid foraging bees.
  • Do not enter treated areas for irrigation activities for 6 days.  Do not re-enter for scouting for 12 hours.

Dibrom

(naled)
 
Group 1B
1.1 L/ha
(450 mL/acre)
 
Apply in 100 to 300 L/ha (40 to 120 L/acre) of water
4
  • Application during hot weather may result in crop injury.
  • Do not apply in temperatures above 32°C.
  • Maximum 2 applications per season.
  • Do not enter treated area for 48 hours.

Decis 5 EC

(deltamethrin)
 
Group 3
100 to150 mL/ha
(40 to 60 mL/acre)
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
1
  • Do not use more than 3 times per season.
  • Will kill beneficials.
  • Repeated use may result in severe reductions of beneficial arthropods.
  • Apply only once to muck soils, before August 1st.

Matador 120EC/ Silencer 120EC

(lambda-cyhalothrin)
 
Group 3
83 mL/ha
(34 mL/acre)
7
  • Allow a 7 day interval between treatments.
  • Do not apply more than 250 mL/ha (100 mL/acre) of product per season.
  • Toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 24 hours.

Pounce EC

(permethrin)
180 to 260 mL/ha
(70 to 105 mL/acre)
1
  • Use the higher rate for heavy infestations.
  • Repeat as necessary.
  • Use sufficient water for complete coverage.
  • Very toxic to bees. Avoid spraying when bees are foraging.

Mako

(cypermethrin)
 
Group 3
62.5 to 125 mL/ha
(26 to 51 mL/acre)
 
Apply in 200 to 500 L/ha (80 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 2 times per year.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Up-Cyde 2.5 EC

(cypermethrin)
 
Group 3
140 mL per ha
(55 mL per acre)
 
Apply in 100 to 500 L/ha (40 to 200 L/acre) of water
7
  • Repeat using a 10 day interval.
  • Do not apply more than 3 times per season.
  • Very toxic to bees. Avoid spraying when bees are foraging.
  • Do not enter treated area for 12 hours.

Surround WP

(kaolin)
 
Used in organics
 
6.25 to 12.5 kg/ha
(2.5 to 5.1 kg/acre)
 
Apply in 250 L/ha (100 L/acre) of water
0
  • Apply at 7 to 14 day intervals.
  • Forms a barrier film on plant surfaces.
  • Surround WP (PCP# 27469) is OMRI-Canada listed.  Check with your certification body before using on an organic operation.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI-Canada = Organic Materials Review Institute of Canada.

Loopers, cutworms and other caterpillars are the larval stages of moths and butterflies. Loopers are usually green with thin white stripes along the body. Cutworms and other caterpillars may be green, brown or gray. They vary in size and can measure up to 5 cm long when fully grown. There are one or more generations each season, depending on the species

Chemical Control

When insecticides are used routinely for aphid and flea beetle control, loopers and caterpillars will also be controlled. When monitoring programs reduce spray applications, loopers and caterpillars may reach a damaging level and require specific treatment. For best control, these pests should be sprayed when small. See table below.

Chemical Control of Loopers

Product Rate PHI* Comments

Dipel  2X DF

(Bacillus thuringiensis)
 
Used in organics
560 to 1120 g/ha
(225 to 450 g/acre)
 
Apply in 600 L/ha (245 L/acre) water
0
  • Most effective when pests are young.
  • Must be eaten by the caterpillars.
  • Repeat applications as necessary. Check label for intervals.
  • Maximum of 4 applications per season.
  • Dipel products are OMRI-USA listed.  Check with your certification body before using in an organic operation.

Entrust SC

(spinosad)  
 
Used in organics
334 mL/ha
(135 mL/acre)
7
  • Do not apply more than 500 mL/ha (202 mL/acre) per year.
  • Harmful to beneficials.
  • Do not enter treated areas for 12 hours.
  • Entrust products are OMRI-USA listed.  Check with your certification body before using in an organic operation.

Minecto Pro

(abamectin/ cyantraniliprole)

Group 6 & 28

370 mL/ha

(150 mL/acre)

Apply in 200 L/ha (80 L/acre) of water
14
  • Use with 0.1 to 0.5% v/v non-ionic surfactant in the spray mixture.
  • Ensure thorough coverage.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season using the high rate.
  • Do not apply more than 3 times per season using the low rate.
  • Do not apply more than 1.340 L/ha (540 mL/acre) per season.
  • Do not apply for 60 days following an in-furrow or soil application or seed piece treatment with any group 28 insecticide.
  • Check label for plantback intervals.
  • Do not re-enter for 12 hours.

Bioprotec CAF

(Bacillus thuringiensis)
 
Group 11
1.4 to 2.8 L/ha
(0.6 to 1.1 L/acre)
 
Apply in 300 L/ha (120 L/acre) of water
0
  • Most effective when pests are young.
  • Must be eaten by the caterpillars.
  • Repeat applications as necessary. Check label for intervals.

Thuricide-HPC

(Bacillus thuringiensis)
 
Group 11
 
Used in organics
2.0 to 4.25 L/ha
(0.8 to 1.7 L/acre)
 
Apply in 200 L/ha (80 L/acre)
of water
0
  • Most effective when pests are young.
  • Must be eaten by the caterpillars.
  • Repeat applications as necessary. Check label for intervals.
  • Thuricide products are OMRI-USA listed.  Check with your certification body before using in an organic operation.

Exirel

(cyantraniliprole)
 
Group 28
250 to 500 mL/ha
(100 to 200 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Do not make more than 4 applications per growing season.
  • Repeat at 7 day intervals.
  • Do not apply more than 4.5 L/ha (1.8 L/acre) per season.
  • Do not apply for 60 days following a soil or seed treatment application of a group 28 insecticide. 
  • Toxic to bees and certain beneficial insects.  Do not apply when crop is blooming.  Apply early in the morning or late in the evening when bees are not active.
  • Note:  Do not tank-mix or apply in sequence with strobilurin-, copper- or captan-containing fungicides.
  •  Observe a plantback interval of 30 days for legume vegetables, crop group 1A (inlcuding beets, carrots, radish, parsnip, turnip) and crop group 2 (inlcuding beet greens and turnip greens). 
  • Observe a plantback interval of 1 year for crops not on this label.
  • Do not enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI-USA = Organic Materials Review Institute of USA.

Spider mites (<1 mm long) cause damage to the leaves during prolonged warm periods, particularly in mid- to late summer. They feed on the lower leaf surface with piercing mouthparts resulting in pale flecking being visible from the top surface. Mites create webbing for protection and dispersal between plants. Heavy infestations can result in leaves drying up and dropping off.

Control

Spider mites build up as the season progresses, therefore, the crop should be checked weekly. If spider mites appear in early summer, or populations escalate, apply a miticide. Two applications 7 to 10 days apart may be needed, depending on level of infestation. See table below.

Chemical Control of Spidermites

Product Rate PHI* Comments

Malathion 85E

(malathion)
 
Group 1B
735 to 1100 mL/ha
(295 to 445 mL/acre)
 
Apply in 1000 L/ha (405 L/acre) of water
3
  • Do not make more than 1 application per year.
  • Best control is obtained when temperature is above 20°C.
  • Toxic to fish.
  • Do not apply where runoff is likely to occur.
  • Do not apply after expiry date on the container label.
  • Do not re-enter treated area for 12 hours.

Agri-Mek 1.9% EC

(abamectin)
 
Group 6
1.0  L/ha
(400 mL/acre)
 
Apply in 185 L/ha (75 L/acre of water.
14
  • Apply when mites first appear.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season.
  • Do not apply more than 2 L per season.
  • Highly toxic to bees. Avoid spraying when bees are foraging.
  • Do not graze treated crop.
  • Check label for re-entry.

Agri-Mek SC

(abamectin)
 
Group 6
225 mL/ha
(90 mL/acre)
 
Apply in 185 L/ha (75 L/acre of water.
14
  • Use with a non-ionic surfactant at the rate of 0.1 to 0.5% v/v of spray mixture.
  • Apply when mites 1st appear.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season.
  • Do not apply more than 450 mL of Agri-Mek SC per season.
  • Highly toxic to bees. Avoid spraying when bees are foraging.
  • Do not graze treated crop.
  • Check labels for re-entry.

Minecto Pro

(abamectin/ cyantraniliprole)

 

Group 6 & 28

370 to 670 mL/ha

(150 to 270 mL/acre)

Apply in 200 L/ha (80 L/acre) of water
14
  • Use with 0.1 to 0.5% v/v non-ionic surfactant in the spray mixture.
  • Make the 1st application when mites 1st appear.
  • Ensure thorough coverage.
  • Repeat using a 7 day interval.
  • Do not apply more than 2 times per season using the high rate.
  • Do not apply more than 3 times per season using the low rate.
  • Do not apply more than 1.340 L/ha (540 mL/acre) per season.
  • Do not apply for 60 days following an in-furrow or soil application or seed piece treatment with any group 28 insecticide.
  • Check label for plantback intervals.
  • Do not re-enter for 12 hours.

Oberon

(spiromesifen)
 
Group 23
500 to 600 mL/ha
(200 to 240 mL/acre)
 
Apply in 100 L/ha (40 L/acre) of water
7
  • Repeat using a 7 day interval.
  • Do not make more than 2 applications per season.
  • Do not apply more than 1200 mL/ha (480 mL/acre) per crop season.
  • Do not enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

 

Thrips cause damage by feeding with rasping mouthparts on leaf surfaces. Leaves can look silvery, scarred, or bronzed. Black fecal spots are evident in areas where thrips are feeding. Insects are small (<1 mm long), thin, yellow to brown or black, and fast-moving. They can be difficult to find as they are easily disturbed and hide in/under plant parts.

Control

Thrips populations build up as the season progresses. They commonly inhabit headlands, ditches, and flowering crops. thrips are attracted to flowering plants. Once flowers dry down or plants are mowed, thrips move to neighbouring areas, and high thrips populations can occur quickly, therefore, the crop should be checked weekly. Broad spectrum insecticides registered for aphids for other pests will also control thrips.

Wireworms, which are yellowish‑brown, shiny, slender, hard‑bodied worms 3 to 25mm long, are the larval stage of click beetles. In the lower Fraser Valley, two introduced European wireworms have been causing the majority of damage. These European species have what appear to be two dark eyes at the more pointed end of the body. The click beetle stage of the European wireworm is about 1 cm long, and is a fairly uniform dark brown or black colour.

Wireworms generally build up to high levels in pasture or wherever there is longstanding grass or sod. When these areas are ploughed, wireworms remain in the soil and will then bore into newly planted seeds or seedlings of many vegetable crops. Wireworms can destroy plants directly, reduce yields, or cause serious cosmetic damage to root crops such as carrots and potatoes.

Heavy infestations occur in fields previously in sod, or surrounded by wooded or grassy areas. Depending on the species, wireworms may live from 3‑6 years in the soil. The European wireworm life cycle begins with overwintered adult click beetles, which emerge from soil in March or April, and lay eggs for up to 3 months.

Eggs are deposited in the soil, normally near a preferred host such as sod or cereal crops. Within about 6 weeks, the eggs hatch into small larvae. After 3 or 4 growing seasons, these larvae become pupae and then adults, usually in August, and these adults remain in the soil overwinter and emerge to deposit eggs in the following spring.

Monitoring

Before planting, baits of whole-wheat flour can be used to determine the presence of wireworms. This is done by placing 30 g of flour at a depth of 10 cm in the soil using a hand corn planter or a shovel and marking the location of each bait with a stake. To obtain an accurate reading, 30 to 50 baits should be used per hectare. Four days later, dig and examine the baits for wireworms. An average of one or more wireworms per bait can cause severe damage to a crop such as potatoes or corn. In the Fraser Valley, most wireworms are near the soil surface in April and May, and this is the best time to use the baits.

After May, wireworms are deeper in the soil, and so baits will be less effective and you might think the problem is not as bad as it actually is. In the Interior, wireworms may descend to a depth of 60cm in the fall and may not return to near the surface until the soil warms up sometime in May. Attempts to determine the presence of wireworms in these areas before this time may also indicate a lower population than actually exists. Baiting works best when fields have been fallowed in the fall, have low green manure content and no weeds. Baiting results will be inconsistent in recently ploughed fields, or in fields with competing crops or weeds.

Pheromone traps have been developed for the two European species, and these are available from Contech Inc. These traps attract the male click beetles, and can be used to determine what species are in a field, and whether the field is at risk of wireworm damage. Contact us for further information.

Control

When it is known that wireworms are in a particular field, insecticides should be applied as recommended for wireworm control on that crop. Titan ST (clothianidin) is registered as a seed treatment for damage suppression of wireworms. Growers should be aware that it will cause wireworms to stop feeding only temporarily, and that they will eventually recover. See Potato Seed Piece Treatment section of this page for label information.

Pyrinex 480 EC and Pyrifos 15G are registered for control of wireworms on potatoes. See Table 2 for label information. Pyrinex 480 EC gives better and more consistent control than Pyrifos 15G.

To maximize the effectiveness of the granular formulation:

  1. Winter fallow suspect fields: work up in the preceding late summer or fall and keep weeds down until potatoes are seeded.
  2. Apply Pyrifos 15G IN-FURROW, not broadcasted.

Under soil conditions where a minimum of crop residue is present, wireworms will be obliged to feed on the treated potato seed pieces and will be more effectively controlled. Since wireworm problems are increasing each year, use every opportunity available to reduce their numbers. See “Wireworms” section of the Vegetable Production Guide: Pest Management (PDF, 1.2 MB) for more information.

Chemical Control of Wireworms

Product Rate PHI* Comments

Pyrifos 15G

(chlorpyrifos)
 
Group 1B
 
Do not use on crops for export to the USA
100 g of product per 100 m of row 70
  • Apply 11.2 kg of product per ha (4.5 kg per acre), based on 90 cm row spacing in furrow at planting.
  • Every effort should be made to completely incorporate granules.
  • Granule deposits from spills and accumulation at row ends should be covered with soil.
  • Do not make more than one application per season.
  • Do not use both Pyrifos 15G and Pyrinex 480 EC together.
  • See Wireworm text section above for tips to maximizing the effectiveness of granulars.

Pyrinex 480 EC

(chlorpyrifos)
 
Group 1B
 
Do not use on crops for export to the USA
21.6 mL product in 5 L of water per 100 m of row 70
  • Apply 2.4 L of product per ha (970 mL per acre), based on 90 cm row spacing, in furrow at planting.
  • Apply in a 6 inch wide (15 cm) banded spray directly on top of planted seed potatoes in the open furrow.
  • Do not use both Pyrinex 480 EC and Pyrifos 15G together.
  • To avoid phytotoxicity, do not mix with other pesticide products or treat plants that are under extreme drought stress.
  • Note: Pyrinex 480 EC gives better and more consistent control than Pyrifos 15G.
  • Do not enter treated area for 24 hours.

Capture 240 EC

(bifenthrin)
 
Group 3A
 
Note:  No longer produced.  Registration due to expire:  December 31, 2019
8.3 to 14.1 mL product per 100 m of row
 
OR:
 
925 to 1404 mL/ha (at plant)

 

21
  • Apply 925 to 1404 mL/ha as an in-furrow spray or T-band spray at planting.
  • Apply once per year as an in-furrow treatment.
  • Observe plantback interval of 30 days for wheat and 365 days for all other crops not appearing on the label. 
  • Toxic to bees.
  • Do not enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

 

Potato Disease Management

These virus-like diseases (phytoplasmas) are spread by leafhoppers from nearby weeds or forage crops. Aster yellows causes the upper leaves to roll and become yellow to purple in colour. Tubers are soft and small. If planted, such tubers produce only very weak plants. Witches’ broom causes dwarfing of plants, a proliferation of stems, small leaves and numerous tiny tubers. If infected tubers are planted, a mass of shoots will sprout forming a low mound of foliage.

Control

Isolate plantings from forage legume fields where leafhoppers may be numerous. Control leafhoppers in and around potato fields (see “Leafhoppers”, this section).

This disease is characterized by a cream-yellow to brown decay in the vascular ring of the tuber. External symptoms such as discolouration just under the periderm and skin cracks may also be present. In the later stages of disease the entire centre of the tuber breaks down leaving only a thin, outer shell. Tuber symptoms may easily be confused with other disorders. Plants in the field may remain symptomless, or show varying degrees of wilt. Wilted leaflets develop interveinal yellow to necrotic areas and tend to curl upward at the edges. The bacteria spread from infected to healthy seed by way of contaminated equipment and storage containers.

Control

Plant only B.C. certified seed potatoes if possible. Use whole seed if practical. Practice crop rotation and good general sanitation. Avoid using second hand sacks especially for seed. Thoroughly clean and disinfect custom or shared seed cutters and planters between farms. Effective disinfectants are:

Effective disinfectants for bacterial ring rot

Disinfectant Amount per L of Water
Quaternary Ammonium 13 mL
50% Lysol 100 mL
Household Bleach 100 mL

If bacterial ring rot is suspected, contact us or the Plant Health Laboratory.

Several different species of bacteria may be involved in soft rot but all can overwinter on tubers and may be present in soil and especially in water used for irrigation. Wet, cream-coloured decay, often developing a foul odour in advanced stages, can develop in seed pieces after planting, in tubers prior to harvest, or in harvested tubers. Tuber symptoms are most likely to occur with the early and mid-season crop when tubers are harvested under wet and/or warm conditions. Blackleg symptoms may develop on injured stems or under hot field conditions.

Control

  • Avoid excessive soil moisture.
  • If possible, harvest when soil temperatures are less than 10°C. Minimize mechanical damage to tubers during harvesting and handling.
  • Protect harvested tubers from hot sun and desiccation.
  • Cooling potatoes after harvest during hot weather will reduce losses.
  • If it is necessary to wash tubers before marketing, dry them as soon as possible and package them in well-aerated containers.

StorOx (formerly called Oxidate) is registered for control of Bacterial Soft Rot in storage. Follow label precautions carefully to avoid operator and environmental hazards (see Storage section, this chapter, for more details).

This widespread soil fungus causes red to dark-brown cankers on young sprouts and later infections cause brown lesions on stolons and roots. A distinctive symptom is the formation of small aerial tubers on infected stems accompanied by a curling of the upper leaves. Infected plants do not die down normally. Potato tubers have small black specks (scurf) on the surface.

Control

  • Rotate with sod and cereal crops, but be aware of the danger of wireworms which build up in those crops.
  • Avoid planting in cold wet soil.
  • Use seed free of black scurf, if possible.
  • Harvest promptly once the skins are set to reduce the amount of black scurf on the tubers.
  • Treat seed pieces with Maxim PSP (controls seed borne Rhizoctonia only). See Potato Seed Piece Treatments section of this page.

Chemical Control of Rhizoctonia Stem and Stolon Canker and Black Scurf

Group Product Rate PHI* Comments
4 (phenylamide)

Ridomil Gold 480 SL

(metalaxyl-M)
4 to 6 mL of product per 100 m of row 90
  • Tankmix with Quadris F at 4 to 6 mL per 100 m of row.
  • Apply directly over the seed pieces in furrow as a 15-20 cm band prior to row closure.
  • Apply in 30 L/ha (12 L/acre) of water.
  • Apply only one time per season.
  • Do not enter treated area for 12 hours.
  • Observe a plant back interval of 30 days.
  • For control of Colorado potato beetle, potato leafhopper and aphids, tankmix with Actara 240SC (see label for details).

7

(carboxamide) (SDHI)

Vertisan

(penthiopyrad)

15.5 to 31 mL per 100 m row N/A
  • Suppression of stem rot (Rhizoctonia solani) only.
  • Apply in furrow at planting, using 1.4 to 1.75 L water/100 row meters.
  • Do not apply more than 1.75 L/ha (710 mL/acre).
  • Do not apply more than 5 L/ ha (2 L/acre) per season.
  • Do not re-enter for 12 hours.

7

(carboxamide) (SDHI)

Sercadis

(fluxapyroxad)

Based on 36 inch row-spacing, use 30 mL per 1000 m of row (333 mL/ha or 135 mL/acre).
 
See label for other row-spacing.
N/A
  • Controls Rhizoctonia canker only.
  • Apply at planting as an in-furrow spray just before the seed is covered with soil.
  • Direct spray pattern as a 10 to 20 cm (4 to 8 inch) band to uniformly cover seed pieces and surrounding soil.
  • Do not apply more than 1.0 L/ha (405 mL/acre) per season
  • No more than 2 consecutive applications before alternating with a fungicide with a different mode of action.
  • Do not enter treated area for 12 hours.
  • For crops not listed, observe a plantback interval of 1 year.

7

(carboxamide) (SDHI)

Aprovia

(benzovindiflupyr)

500 to 750 mL/ha
(200 to 300 mL/acre) 
 
or
 
4.5 to 6.8 mL per 100 m of row (based on 90 cm row spacing)
 
Apply in 50 to 150 L/ha (20 to 60 L/acre) of water
N/A
  • Suppression only.
  • Apply as an in-furrow spray, directing the spray into the furrow as a 15 to 20 cm band just before the seed is covered.
  • Do not apply more than 750 mL/ha (300 mL/acre) per application.
  • Do not apply more than 100 g a.i./ha (40 g a.i./acre) of benzovindiflupyr-containing products on potato crops per season if an in-furrow application is made.
  • Observe a plantback interval of 6 months for crops not listed.
  • Do not re-enter treated area for 12 hours.

11 & 7

(amide/strobilurin)

Elatus

(benzovindiflupyr/

azoxystrobin)

See rate conversion chart of label for rates per 100 m row.
 
Apply in 50 to 150 L/ha (20 to 60 L/acre) of water.
N/A
  • Make an in-furrow application at planting.
  • Do not apply more than 1.5 kg/ha (0.6 kg/acre) per season.
  • Observe a plantback interval of 6 months for crops not listed.
  • Also controls black dot when used as a foliar spray.  Check label. 

 

Serenade Soil

(QST 713 strain of
dried Bacillus subtilis)
 
Used in organics.
2.7 to 14 L/ha
(1.1 to 5.7 L/acre)
0
  • Suppression only.
  • Serenade Soil (PCP# 30666) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.

In-Furrow Application:

  • Apply in a narrow band with the spray directed at the seed and surrounding soil  before covering the seed or seed piece.

Post-plant applications:

  • After crop germination, additional applications may be made to the soil as a drench or spray directed towards the base of the plant.
  • Irrigate to move material into the seed or root zone within 24 hours.
  • Repeat at 21 to 28 day intervals.
44

Double Nickel 55

(Bacillus amyloliqufaciens strain D747)

Soil application:  
0.2 to 1 kg/ha
(80 to 400 g/acre)
N/A
  • Suppression of Black scurf (Rhizoctonia solani) only.
  • Apply as a 10 to 15 cm (4 to 6 inch) wide banded spray directly over the seeds in-furrow just before they are covered with soil.
  • See banded/in-furrow rate conversion chart of label for the amount of product per 100 meters of row that will provide the desired application rate based on row spacing.
  • Do not use highly alkaline or highly acidic water to mix sprays.
  • If necessary, use a buffering agent to maintain a pH of 6 to 8 in the water of the tank.
  • Do not re-enter treated area for 4 hours.
44

Double Nickel LC

(Bacillus amyloliqufaciens strain D747)

Soil application:
1 to 5 L/ha
(0.4 to 2 L/acre)
N/A
  • Suppression of Black scurf (Rhizoctonia solani) only.
  • Apply as a 10 to 15 cm (4 to 6 inch) wide banded spray directly over the seeds in-furrow just before they are covered with soil.
  • See banded/in-furrow rate conversion chart of label for the amount of product per 100 meters of row that will provide the desired application rate based on row spacing.
  • Do not use highly alkaline or highly acidic water to mix sprays.
  • If necessary, use a buffering agent to maintain a pH of 6 to 8 in the water of the tank.
  • Do not re-enter treated area for 4 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI- Canada = Organic Materials Review Institute of Canada

The soft rot bacteria causing blackleg overwinter in infected volunteers and in the lenticels of symptomless tubers. Dark brown or black discolouration occurs at the base of the stem and tubers may show black rot at stem end. Individual stems or entire plants wilt. The disease is favoured by cool, wet soil, continuous potato cropping and infection by tuber rot fungi such as Fusarium.

Control

  1. Disinfect the cutting knife after cutting partially rotted tubers.
  2. Disinfect custom or shared seed cutters or planters between farms (see Bacterial Ring Rot, this section).
  3. While seed-piece dust treatments do not directly control the black leg bacterium, they prevent early rotting of the seed-piece and have been found to indirectly reduce field incidence of black leg (see Fusarium Rot). See Potato Seed Piece Treatments section of this page for more information.
  4. Use of small, whole seed is an effective preventive measure when practical.
  5. Remove cull piles, refuse and volunteer potatoes.

Early blight occurs in all areas of the province but is more common in the Interior than it is at the Coast. Early blight first appears as small black spots on leaves which may enlarge to one cm or more in diameter. Infected leaves eventually become yellow and necrotic. A severely blighted plant will have hundreds of infections on it, in contrast to a plant infected with late blight which usually has only a few extensive infections which expand continuously until all the foliage is rotted.

Control

  1. If possible, turn under crop residue promptly after harvest.
  2. Avoid replanting fields which had a severe early blight problem the previous year.
  3. Ensure adequate nitrogen fertility.
  4. Keep weeds under control.
  5. A spray program for late blight will also help to control early blight (see table below).

Chemical Control of Early Blight

Group Product Rate PHI* Comments
(biological)

Serenade Opti

(Bacillus subtilis)

Used in organics

1.1 to 2.2 kg/ha

(450 to 900 g/acre)
0
  • Suppression only.
  • Repeat using a 7 to 10 day interval.
  • Serenade Opti (PCP# 31666) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.
M5 
(chloronitrile)

Bravo ZN

(chlorothalonil)

1.6 to 2.4 L/ha
(0.6 to 1.0 L/acre
2
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M5 
(chloronitrile)

Echo 90DF

(chlorothalonil)

0.9 to 1.3 kg/ha
(400 to 500 g/acre)
1
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M5
(chloronitrile)

Echo 720

(chlorothalonil)

1.1 L/ha
(400 mL/acre)
1
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M
(phthalimide)

Maestro 80 DF

(captan)

2.5 to 3.75 kg/ha
(1.0 to 1.5 L/acre)
7
  • Use sufficient water volume to obtain thorough coverage.
  • Begin treatment when conditions are favourable for disease.
  • Repeat at 7 to 10 day intervals.
  • Do not apply more than 7 times per season.
  • Do not enter treated area for 48 hours.

M

(dithiocarbamate)

Dithane DG
Rainshield NT

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Use low rate when plants are 10 to 15 cm high, increase to 1.75 kg/ha (0.7 kg/acre) as plant size increases, and use high rate at row closure.
  • Repeat at 7 to 10 day interval.
  • During periods of vigorous crop growth, spray intervals may be reduced to 5 to 6 days using the medium rate after row closure until conditions allow return to the regular spray schedule.

M

(dithiocarbamate)

Dithane F-45

(mancozeb)

1.8 to 3.8 L/ha
(0.7 to 1.5 L/acre)
1
  • Use low rate when plants are 10 to 15 cm high, increase to 3.0 L/ha (1.2 L/acre) as plant size increases, and use high rate at row closure.
  • Repeat at 7 to 10 day intervals.
  • During periods of vigorous crop growth, spray intervals may be reduced to 5 to 6 days using the medium rate after row closure until conditions allow return to the regular spray schedule.

M

(dithiocarbamate)

Penncozeb 75DF

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Apply every 7 to 10 days, shorten to 5 to 6 days if conditions are severe.
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Begin applications early using the low rate and increasing as the vines increase in size.
  • Do not enter treated area for 24 hours.

M

(dithiocarbamate)

Penncozeb 75DF Raincoat

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Apply every 7 to 10 days, shorten to 5 to 6 days if conditions are severe.
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Begin applications early using the low rate and increasing as the vines increase in size.
  • Do not enter treated area for 24 hours.
M
(dithiocarbamate)

Polyram DF

(metiram)

Note:  no longer produced.

1.1 to 1.75 kg/ha
(450 to 700 g /acre)
1
  • Apply at 7 to 10 day intervals using 1.1 to 1.75 kg/ha (0.45 to 0.7 kg/acre) until plants cover the row.
  • Use 1.10 to 1.75 kg/ha (0.45 to 0.7 kg/acre) at 5 to 7 day intervals starting when plants are 15 cm high and continuing until top killing.
M
(dithiocarbamate)

Manzate DF

(mancozeb)

1.1 to 2.24 kg/ha
(450 to 900 g/acre)

Apply in 200 to 1000 L/ha (80 to 405 L/acre) of water
1
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Apply at 7 to 10 day intervals.
  • During periods of wet weather favourable for disease development, spray intervals may be reduced to 5 to 6 days.
M
(inorganic)

Parasol F

(copper hydroxide)
0.8 to 1.8 L/ha
(320 to 720 mL/acre)
1
  • Also controls late blight.  Check label.
  • Combine with 1.75 to 2.25 kg/ha (700 to 900 g/acre) mancozeb 80%.
  • Apply at 7 to 10 day intervals, starting when plants are 15 cm high.
  • Maximum 10 applications per season.
  • Apply at vine kill with a desiccant, or alone after vine kill at 2.4 L/ha (960 mL/acre). This may prevent late blight infection of tubers during harvest.
M
(inorganic)

Kocide 2000

(copper hydroxide)

 

Used in organics.

0.8 to 1.6 kg/ha
(300 to 350 g/acre)
1
  • Also controls late blight.  Check label.
  • Apply at 7 to 10 day intervals, starting when plants are 15 cm high.
  • Apply 2.4 kg/ha (1 kg/acre) at vine kill with a desiccant or just prior to harvest. This may reduce Late Blight infection of tubers during harvest.
  • Can be combined with Manzate DF at 1.75 to 2.25 kg/ha (700 to 900 g/acre).
  • Kocide 2000 (PCP# 27348) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.
M
(inorganic)

Copper Spray

(Fixed Copper)

4.0 kg/ha (1.6 kg/acre)

Apply in 1000 L/ha (405 L/acre) of water
1
  • Apply every 7 to 10 days beginning when plants are 10 to 20 cm high, increasing the rate as the vines increase in size.
  • Maximum 10 applications per season.
  • Do not enter treated area for 48 hours.
M
(inorganic)

Copper Oxy-chloride 50

(copper hydroxide)

4.0 kg/ha (1.6 kg/acre)

Apply in 1000 L/ha (405 L/acre) of water
1
  • Apply every 7 to 10 days beginning when plants are 10 to 20 cm high, increasing the rate as the vines increase in size.
  • Maximum 10 applications per season.
  • Do not enter treated area for 48 hours.
M
(inorganic)

Copper 53W

(tri-basic copper sulphate)
3.8 kg/ha
(1.5 kg/acre)
1
  • Apply when plants are 12 to 18 cm high.
  • Repeat at 7 to 10 day intervals.
  • Maximum 10 applications per season.
M1
(inorganic)

Cueva

(copper octanoate)

Use a 0.5%  to 2%  solution at 470 to 940 L/ha (190 to 380 L/acre) 1
  • Also controls late blight.  Check label.
  • For a 0.5% solution, mix 1 part Cueva to 200 parts water.
  • For a 2% solution, mix 1 part Cueva to 50 parts water.
  • Repeat at 7 to 10 day intervals.
  • Repeat at 5 to 7 day intervals following heavy rain or when disease pressure is high.
  • Repeat at 5 to 7 day intervals following heavy rain or when disease pressure is high.
  • Do not make more than 15 applications per year.
  • Time applications so that 12 hours of dry weather follow application.
  • Do not re-enter treated area for 4 hours.

M4 
(acylamines/

dithiocarbamate)

Ridomil Gold/ Bravo Twin Pak

(metalaxyl-M/ chlorothalonil)

Note:  no longer produced.

Ridomil MZ 68 WP

(metalaxyl/ mancozeb)

See label for specific rates N/A
  • Due to widespread resistance development in B.C., these products may not effectively control blight. 
  • Do not contaminate water.
  • Do not use on gravelly soils, soils with a high water table or less than 2% organic matter.
  • Do not tank mix with a top-killer.

3

(triazole)

Quash

(metconazole)

175 to 280 g/ha
(70 to 115 g/acre)

Apply in 200 L/ha (80 L/acre) of water
1
  • Repeat using a 7 to 14 day interval.
  • Do not make more than 3 applications at the high rate or more than 4 applications at the low rate.
  • Do not apply more than 840 g/ha (340 g/acre) per season.
  • Application should not be made if rain is expected within 2 hours of application.
  • Observe a 30 day plantback interval for all crops not listed on label.
  • Do not re-enter treated area for 12 hours.

3

(isopropanol-triazole)

Cevya

(mefentrifluconazole)

0.19 to 0.25 L/ha (77 to 100 mL/acre) 7
  • Repeat using  a 7 to 14 day interval.
  • Make an additional application, if necessary.
  • Do not apply more than 1.125 L/ha (455 mL/ac) per year.
  • Do not re-enter treated area for 12 hours.

7

(carboxamide)

succinyl dehydrogenase inhibitor (SDHI) class

Luna Privilege

(fluopyram)

 

Note:  no longer produced.

150 to 300 mL/ha
(60 to 120 mL/acre)
7
  • Repeat using a 7 to 12 day interval.
  • Do not apply more than 800 mL/ha (325 ml/acre) per season.
  • Observe a plantback interval of 30 days for cereals and corn.
  • Do not enter treated area for 12 hours.

7
(carboxamide)

succinyl dehydrogenase inhibitor (SDHI) class

Velum Prime

(fluopyram)

500 mL/ha 

or

4.5 mL of product per 100 m of row (based on 90 cm row spacing)
N/A
  • Suppression only.
  • Apply in 50 to 150 L/ha (20 to 60 L/acre of water.
  • Apply in a 10 to 15 cm band in-furrow at planting, directing the spray to the seed and soil just before the seed is covered.
  • Use a another mode of action or group number for the first foliar fungicide application.
  • Observe a plant back interval of 14 days for alfalfa.
  • Do not re-enter treated area for 12 hours.

7
(pyridine-

carboxamide)

Lance WDG

(boscalid)

175 to 315 g/ha
(170 to 126 g/acre)

Apply in at least 100 L/ha (40 L/acre) of water.
30
  • Repeat at 14 day intervals.
  • Maximum of 4 applications per season.
  • No more than two consecutive applications before alternating to a fungicide with a different mode of action.
  • Do not enter treated area for 12 hours.
  • For crops not on the label, observe a plant back interval of 14 days.

7
(pyridine-

carboxamide)

Cantus WDG

(boscalid)
175 to 315 g/ha
(170 to 126 g/acre)

Apply in at least 100 L/ha (40 L/acre) of water.
30
  • Repeat using a 14 day interval.
  • Maximum of 4 applications per season.
  • No more than two consecutive applications before alternating to a fungicide with a different mode of action.
  • Do not enter treated area for 12 hours.
  • For crops not on the label, observe a plant back interval of 14 days.

7

(carboxamide)

Vertisan

(penthiopyrad)

1 to 1.75 L/ha
(400 to 700 mL/acre)
Apply in 110 L/ha (45 L/acre) of water
7
  • Suppression only.
  • Repeat using a 7 to 14 day interval.
  • Do not apply more than 5 L/ha (2 L/acre) per season.
  • Do not re-enter treated area for 12 hours.

7

(carboxamide (SDHI))

Sercadis

(fluxapyroxad)

167 to 333 mL/ha
(68 to 135 mL/acre)

Apply in 100 L/ha (40 L/acre) of water
7
  • Use with a non-ionic surfactant (0.125% v/v).
  • Repeat using a 7 to 14 day interval.
  • Do not make more than 3 applications per season.
  • Do not apply more than 1.0 L/ha (405 mL/acre) per season
  • No more than 2 consecutive applications before alternating with a fungicide with a different mode of action.
  • Do not enter treated area for 12 hours.
  • For crops not listed, observe a plantback interval of 1 year.

3 & 7

(amide/triazole)

Aprovia Top

(benzovindiflupyr/ difenoconazole)

643 to 967 mL/ha
(260 to 391 mL/acre)
 
Apply in 150 L/ha (60 L/acre) of water.
14
  • Apply as a foliar spray.
  • Repeat using a 7 to 14 day interval.
  • Do not make more than 4 applications per season.
  • Do not apply more than 3.9 L/ha (1.6 L/acre) per season.
  • Observe a plantback interval of 60 days for sweet corn and 6 months for crops not listed.
  • Do not re-enter treated area for 12 hours.

9

(anilnopyrimidine)


(chloronitrile)

Scala SC

(pyrimethanil)

Plus: 

Bravo 500

(chlorothalonil)

750 mL/ha
(305 mL/ acre)

Plus:

1.6 to 2.4 L /ha
(650 to 970 mL/acre)

7
  • Begin applications when plants are 15 to 20 cm tall, or when disease threatens (whichever comes first).
  • Repeat at 7 day interval.
  • Do not apply more than 6 times per year.
  • Wheat may be planted 30 days following the application of Scala SC.
  • For all crops not listed on the label, observe a plant-back interval of 30 days.
  • Apply in 300 L/ha (121 L/acre) of water.

11/ M2

(strobilurin/ dithiocarbamate) 

Cabrio Plus

(pyraclostrobin/ metiram)

Note:  no longer produced. 

2.25 to 3.35 kg/ha

(0.91 to 1.36 kg/acre)

Apply in 200 L/ha (80 L/acre) of water. 

3
  • Apply using a 7 to 14 day interval.
  • Do not apply more than 3 times per season.
  • Do not enter treated area for 12 hours.
  • Observe a plantback interval of 14 days for all crops not listed.
  • Crop can be fed or grazed to livestock.
11/M 
(strobilurin)

Reason 500SC

(fenamidone)

Plus:

Dithane DG Rainshield NT

(mancozeb)

Or

Bravo 500

(chlorothalonil)

200 mL/ha
(81mL/acre)

Plus:

1.25 kg/ha
(500 g/acre)


Or

1.25 L/ha
(500 mL/acre)
14
  • Also controls late blight.  Check labels.
  • Begin application when plants are 15 to 20 cm high, or when disease threatens (whichever comes first).
  • Tank mix with Dithane DG or Bravo 500.
  • Do not apply more than 6 times per year.
  • Observe a 30 day plant back interval for all crops.
  • Do not enter treated area until residues have dried.
11
(strobilurin)

Quadris F

(axosystrobin)

500 to 800 mL/ha
(200 to 300 mL/acre)
1
  • Also controls black dot.  Check label.
  • Do not use when late blight is present.
  • Repeat applications at 7 to 14 day intervals.
  • Do not make more than 3 applications per season.
  • Do not re-enter treated area for 12 hours.
  • Can also be tank-mixed with 2 L/ha (800 mL/acre of Bravo 500.
  • Observe a plant back interval of 30 days for potatoes and other root crops.
11
(strobilurin)

Headline EC

(pyraclostrobin)
450 to 670 mL/ha
(200 to 270 mL/acre)
3
  • Apply using a 7 to 14 day interval.
  • No more than two consecutive applications before alternating to a fungicide with a different mode of action.
  • Do not apply more than 3 times per season.
  • Do not enter treated area for 12 hours.

11 U
(strobilurin/

miscellaneous)

Tanos 50 DF

(famoxadone / cymoxanil) 

560 to 840 g/ha
(224 to 326 g/acre)

Apply in 250 L/ha (100 L/acre) of water
14
  • Maximum of 6 applications per year.
  • For late blight control, make the first application following one or two applications of a preventative, broad spectrum fungicide such as chlorothalonil or mancozeb.
  • Apply at 7 day intervals.
  • Observe a minimum plant back interval of one year for crops not on the label.
  • Do not enter treated area for 24 hours.
  • Harmful to beneficials.
  • Do not apply to stressed plants.

11 & 3

(strobilurin/

triazole)

Quadris Top

(azoxystrobin/ difenoconazole)

566 to 1000 mL/ha
(229 to 405 mL/acre)
 
Apply in 150 L/ha (60 L/acre) of water.
14
  • Also controls black dot.  Check label.
  • Do not apply more than once for black dot.
  • Repeat at 7 to 14 day intervals for early blight.
  • Do not make more than 3 applications per year.
  • Do not re-enter treated areas for 12 hours.
  • Observe a plant back interval of 60 days for all crops not registered on this label or the Inspire label.

11 & 7

(amide/

strobilurin)

Elatus

(benzovindiflupyr/ azoxystrobin)

417 to 500 g/ha
(169 to 204 g/acre)
 
Apply in 150 L/ha (60 L/acre) of water.
14
  • Also controls black dot.  Check label.
  • Apply as a foliar spray.
  • Repeat at 7 to 14 days.
  • Do not make more than 3 applications per season.
  • Do not apply more than 1.5 kg/ha (0.6 kg/acre) per season.
  • Observe a plantback interval of 6 months for crops not listed.
19
(polyoxin)

Diplomat 5SC

(polyoxin D zinc salt)
537 to 926 mL/ha
(217 to 375 mL/acre)
0
  • Suppression only.
  • Repeat using a 7 to 14 day interval.
  • Do not apply more than 2.8 L/ha (1.1 L/acre) per season.

22
(benzamide)

 

 

M
(dithiocarbamate)

 

22
(benzamide)

 

 

 

M
(dithiocarbamate)

Zoxium 80W

(zoxamide)

Plus:

Dithane DG Rainshield NT

(mancozeb)

Or

Zoxium 80W

(zoxamide)

Plus:

Dithane DG Rainshield NT

(mancozeb)

175 g/ha
(70 g/acre)

 

 

Plus:

1.5 kg/ha
(600 g/acre)
 

 

 

Or

235 g/ha
(94 g/acre)

 

Plus:


(800 g/acre)
3
  • Also controls late blight.  Check labels.
  • Always tank mix with Dithane DG.
  • Repeat at 7 day intervals.
  • Maximum of 6 applications per season.
  • A 30 day plant back interval (PBI) is required for leafy vegetables and root and tuber vegetables. For all other crops not included on the label, the PBI is 140 days.
  • Do not enter treated area for 48 hours.

22 & M3
(dithiocarbamate/

benzamide)

Gavel DF

(mancozeb / zoxamide)
1.7 kg/ha
(700 g/acre)
3
  • Repeat at 7 day intervals.
  • Maximum of 6 applications per season.
  • A 30 day plant back interval (PBI) is required for leafy vegetables and root and tuber vegetables. For all other crops not included on the label, the PBI should be 140 days.
  • Do not enter treated area for 48 hours.
44

Double Nickel 55

(Bacillus amyloliqufaciens strain D747)

0.5 to 2 kg/ha
(200 to 810 g/acre)
 
For smaller plants or low disease pressure:  
0.5 to 1 kg/ha
(200 to 400 g/acre)
0
  • Suppression only.
  • Apply as a foliar spray at row closure to tuber formation.
  • Repeat at 3 to 10 day intervals.
  • Do not use highly alkaline or highly acidic water to mix sprays.
  • If necessary, use a buffering agent to maintain a pH of 6 to 8 in the water of the tank. 
  • Do not re-enter treated area for 4 hours.
44

Double Nickel LC

(Bacillus amyloliqufaciens strain D747)

2.5 to 10 L/ha
(1.0 to 4 L/acre)
For smaller plants or low disease pressure:   
2.5 to 5 L/ha
(1.0 to 2 L/acre)
0
  • Suppression only.
  • Apply as a foliar spray at row closure to tuber formation.
  • Repeat at 3 to 10 day intervals.
  • Do not use highly alkaline or highly acidic water to mix sprays.
  • If necessary, use a buffering agent to maintain a pH of 6 to 8 in the water of the tank. 
  • Do not re-enter treated area for 4 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI- Canada = Organic Materials Review Institute of Canada

Dry Rot and Seed-Piece Decay

Decay occurs in storage or after seed-piece is planted.

Control

  1. Wait until soil warms up before planting.
  2. Seed piece treatments - originally intended for protection against fusarium dry rot, seed piece treatments now have a bigger role to play. It is recommended that a seed piece treatment also contain some mancozeb to provide protection against the transfer of late blight spores at seed cutting time. The following products all contain mancozeb.
  3. Products containing captan or thiophanate-methyl (Senator PSPT), or fludioxonil (Maxim PSP), or metiram (Polyram 16D) will control dry rot, but not late blight spores. See Table 4.
  4. To reduce losses in storage, especially in crops which are to be stored for a long period or in processing crops which must be stored at warm temperatures, a post-harvest fungicide application may be beneficial.  Apply Mertect in a fine spray to all surfaces of tubers. Use 7.5 L of Mertect per 170 L of water applied at 2 L of this solution per tonne of potatoes. Where resistant strains of Fusarium and/or silver scurf exist, the Mertect treatment will be ineffective against them.
  5. Another option for post-harvest control of table and processing potatoes is Stadium (azoxystrobin/ difenoconazole/ fludioxonil).  Apply Stadium using the rate of 32.4 mL per tonne of potatoes at a final spray solution (total slurry volume) of 2 L per metric tonne of potatoes.  Treated potatoes should be barely wet.  Apply as an in-line aqueous spray ensuring that tubers are rotating along a conveyor into storage during treatment.  Also, ensure tubers are tumbling as they are treated with a full flow of potatoes maintained on the conveyor (reducing open space between tubers).  Do not apply to seed potatoes.  Do not make more than 1 post-harvest application to the tubers.  Also provides suppression of Siver Scurf (see Silver Scurf section).
  6. For seed potatoes only, a more reliable treatment for Fusarium dry rot is Dithane F-45. Apply 1.58 L of Dithane F-45 in 4 to 8 L water per tonne of seed potatoes as a conveyer belt spray going into storage. Treated seed must not be used for food or feed.

StorOx (formerly called Oxidate) is registered for control of Fusarium Rot in storage. Follow label precautions carefully to avoid operator and environmental hazards (see Storage section of this page for more details).

Late blight occurs in all areas of the province but it is more dependent on rainfall than early blight and is more likely to reach epidemic proportions at the Coast. Water-soaked to gray spots appear at tips or margins of leaves, in leaf axils and on stems. Spots spread over plant surface. Rate of spread increases in moist weather and under sprinkler irrigation. Blight causes dry or wet rot of tubers in field and in storage.

Monitoring

Potato integrated pest management (IPM) in the Fraser Valley involves commercially available insect and disease monitoring services. Monitoring for late blight provides growers with the information needed to accurately time pesticide sprays and avoid unnecessary spraying.

Control

  1. Avoid replanting fields which had severe late blight the previous year.
  2. Destroy culls and volunteers. Remove them from the farm or cover completely with a plastic sheet so that the fungus will not grow and sporulate. Kill any sprouts that appear on cull piles with herbicides.
  3. Carefully grade out suspicious looking tubers when preparing seed for planting. Discard tubers that are partially decayed or mummified but still sound enough to send up some sprouts. Dispose of them in a secure manner off your farm if possible and where they will not be able to grow. The seed to be planted should be treated with a fungicide containing mancozeb, which has been shown to reduce late blight transmission from infected tubers.
  4. If using floating mulches or row covers on early potatoes, apply a fungicide as soon as the cover is removed. Curzate 60 DF is the preferred material as it has some “kick-back” activity on blight infections. Covers encourage early succulent growth and blight infections. Blight becomes established in these earlier and then spreads to later crops.
  5. Separate fields of early, second early and late crops as much as possible to slow down the spread of spores from the earlier to the later crops. Early crops should not be planted upwind of later crops.
  6. Ensure potatoes are well hilled.
  7.  Begin a spray program as soon as advised by your IPM scout or before row closure. When disease pressure is severe the following spray program is suggested:
    • Apply a systemic fungicide such as Curzate 60 DF, Acrobat 50WP, Quadris F, or Tanos at least once before row closure. Each of these fungicides is permitted a maximum of 3 applications per year.
    • Apply products listed in the table below through the growing season as recommended by your IPM scout or on a 5 – 10 day schedule.
    • Apply Acrobat 50WP to cover soil and stems after top-kill if blight is present or conditions are wet. See also Potato Blight Fungicide Table below.
  8. If blight gets out of control, top-kill the crop and apply one more Acrobat 50WP application when the tops are about half dead. Note: The PHI for Acrobat is 4 days.
  9. Harvest in dry weather when vines have been dead for at least two weeks. This will reduce chances of tuber infection during the harvest operation and will also allow recognition and grading out of tubers that were infected in the field. If infected tubers and wet soil go into storage, the pathogen may sporulate and spread to other tubers.
  10. Solanaceous weeds such as Hairy nightshade are hosts of late blight. Check adjacent crops and weedy areas around the edges of fields for this weed and if found, it should be controlled to prevent a build-up of inoculum.

Chemical Control of Late Blight

Group Product Rate PHI* Comments
M5 
(chloronitrile)

Bravo ZN

(chlorothalonil)

1.2 to 2.4 L/ha
(0.5 to 1.0 L/acre)
2
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M5 
(chloronitrile)

Echo 90DF

(chlorothalonil)

0.7 to 1.3 kg/ha
(300 to 500 g/acre)
1
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M5 
(chloronitrile)

Echo 720

(chlorothalonil)

0.8 to 1.7 L/ha
(300 to 700 mL/acre)
1
  • This is the preferred a.i. for Interior areas where early blight is a serious problem.
  • Repeat using 7 to 10 day intervals.
  • Do not apply more than 3 times per year.
  • Mixers and loaders must use a closed system.
  • Applicators must use groundboom equipment with an enclosed cab.
  • Table & Seed Potatoes:  Do not re-enter treated area for 23 days for handset irrigation; 3 days for scouting and 12 hours for all other activities.
  • Seed Potatoes:  Do not re-enter treated area for 19 days for roguing.
M
(phthalimide)

Maestro 80 DF

(captan)

2.5 to 3.75 kg/ha
(1.0 to 1.5 L/acre)
7
  • Use sufficient water volume to obtain thorough coverage.
  • Begin treatment when conditions are favourable for disease.
  • Repeat at 7 to 10 day intervals.
  • Do not apply more than 7 times per season.
  • Do not enter treated area for 48 hours.

M

(dithiocarbamate)

Dithane DG
Rainshield NT

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Use low rate when plants are 10 to 15 cm high, increase to 1.75 kg/ha (0.7 kg/acre) as plant size increases, and use high rate at row closure.
  • Repeat at 7 to 10 day interval.
  • During periods of wet weather favouring late blight and/or vigorous crop growth, spray intervals may be reduced to 5 to 6 days using the medium rate after row closure until conditions allow return to the regular spray schedule.

M

(dithiocarbamate)

Dithane F-45

(mancozeb)

1.8 to 3.8 L/ha
(0.7 to 1.5 L/acre)
1
  • Use low rate when plants are 10 to 15 cm high, increase to 3.0 L/ha (1.2 L/acre) as plant size increases, and use high rate at row closure.
  • Repeat at 7 to 10 day intervals.
  • During periods of wet weather favouring late blight and/or vigorous crop growth, spray intervals may be reduced to 5 to 6 days using the medium rate after row closure until conditions allow return to the regular spray schedule.

M

(dithiocarbamate)

Penncozeb 75DF

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Apply every 7 to 10 days, shorten to 5 to 6 days if conditions are severe.
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Begin applications early using the low rate and increasing as the vines increase in size.
  • Do not enter treated area for 24 hours.

M

(dithiocarbamate)

Penncozeb 75DF Raincoat

(mancozeb)

1.1 to 2.25 kg/ha
(450 to 900 g/acre)
1
  • Apply every 7 to 10 days, shorten to 5 to 6 days if conditions are severe.
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Begin applications early using the low rate and increasing as the vines increase in size.
  • Do not enter treated area for 24 hours.
M
(dithiocarbamate)

Polyram DF

(metiram)

Note:  no longer produced.

1.1 to 1.75 kg/ha
(450 to 700 g /acre)
1
  • Apply using a 7 to 10 day interval using 1.1 to 1.75 kg/ha (0.45 to 0.7 kg/acre) until plants cover the row.
  • Use 1.10 to 1.75 kg/ha (0.45 to 0.7 kg/acre) at 5 to 7 day intervals starting when plants are 15 cm high and continuing until top killing.
M
(dithiocarbamate)

Manzate DF

(mancozeb)

1.1 to 2.24 kg/ha
(450 to 900 g/acre)

Apply in 200 to 1000 L/ha (80 to 405 L/acre) of water
1
  • Apply 1.1 kg/ha when plants are 10 to 15 cm high, increase to 1.75 kg/ha as plant size increases, and to 2.25 kg/ha at row closure.
  • Apply at 7 to 10 day intervals.
  • During periods of wet weather favourable for disease development, spray intervals may be reduced to 5 to 6 days.

4 M
(acylamines/

dithiocarbamate)

Ridomil Gold/ Bravo Twin Pak

(metalaxyl-M/ chlorothalonil)

Note:  no longer produced.

Ridomil MZ 68 WP

(metalaxyl/ mancozeb)

See label for specific rates N/A
  • Due to widespread resistance development in B.C., these products may not effectively control blight. 
  • Do not contaminate water.
  • Do not use on gravelly soils, soils with a high water table or less than 2% organic matter.
  • Do not tank mix with a top-killer.

11 M2

(strobilurin/

dithiocarbamate)

Cabrio Plus

(pyraclostrobin/

metiram)

Note:  no longer produced.  

2.25 to 3.35 kg/ha
(0.91 to 1.36 kg/acre)
 
Apply in 200 L/ha (80 L/acre) of water.
3
  • Apply using a 7 to 10 day interval.
  • Do not apply more than 3 times per season.
  • Do not enter treated area for 12 hours.
  • Observe a plantback interval of 14 days for all crops not listed.
  • Crop can be fed or grazed to livestock.

11
(strobilurin)

Headline EC

(pyraclostrobin)

450 to 670 mL/ha
(200 to 270 mL/acre)
3
  • Apply using a 5 to 7 day interval.
  • Tank mix with Bravo 500 or Polyram DF.
  • No more than two consecutive applications before alternating to a fungicide with a different mode of action.
  • Do not apply more than 3 times per season.
  • Do not enter treated area for 12 hours.
11
(strobilurin)

Reason 500SC

(fenamidone)

Plus:

Dithane DG 

Rainshield NT

(mancozeb)

Or

Bravo 500

(chlorothalonil)

200 mL/ha
(81mL/acre)
 

Plus:

1.25 kg/ha
(500 g/acre)

 

Or

1.25 L/ha
(500 mL/acre)

14
  • Also controls early blight.  See labels.
  • Begin application when plants are 15 to 20 cm high, or when disease threatens (whichever comes first).
  • Tank mix with Dithane DG or Bravo 500.
  • Do not apply more than 6 times per year.
  • Observe a 30 day plant back interval for all crops.
  • Do not enter treated area until residues have dried.

11 U
(strobilurin/

miscellaneous)

Tanos 50 DF

(famoxadone /

cymoxanil)

560 to 840 g/ha
(224 to 326 g/acre)

Apply in at least 250 L/ha (100 L/acre) of water
14
  • Maximum of 6 applications per year.
  • Make the first application following one or two applications of a preventative, broad spectrum fungicide such as chlorothalonil or mancozeb.
  • Apply at 7 day intervals.
  • Observe a minimum plant back interval of one year for crops not on the label.
  • Do not enter treated area for 24 hours.
  • Harmful to beneficials.
  • Do not apply to stressed plants.

22
(benzamide)

 

 

M
(dithiocarbamate)

 

22
(benzamide)

 

 

 

M
(dithiocarbamate)

Zoxium 80W

(zoxamide)

Plus:

Dithane DG

Rainshield NT

(mancozeb)

Or

Zoxium 80W

(zoxamide)

Plus:

Dithane DG 

Rainshield NT

(mancozeb)

175 g/ha
(70 g/acre)
 
 
 
Plus:

1.5 kg/ha
(600 g/acre)

 
Or

235 g/ha
(94 g/acre)
 
 
Plus:

2.0 kg/ha
(800 g/acre)
3
  • Also controls early blight.  Check labels.
  • Always tank mix with Dithane DG.
  • Repeat at 7 day intervals.
  • Maximum of 6 applications per season.
  • A 30 day plant back interval (PBI) is required for leafy vegetables and root and tuber vegetables. For all other crops not included on the label, the PBI is 140 days.
  • Do not enter treated area for 48 hours.

22 & M3
(dithiocarbamate/

benzamide)

Gavel DF

(mancozeb / zoxamide)

2.25 kg/ha
(900 g/acre)
3
  • Repeat at 7 day intervals.
  • Maximum of 6 applications per season.
  • A 30 day plant back interval (PBI) is required for leafy vegetables and root and tuber vegetables. For all other crops not included on the label, the PBI should be 140 days.
  • Do not enter treated area for 48 hours.
M
(inorganic)

Parasol F

(copper hydroxide)

0.8 to 1.8 L/ha
(320 to 720 mL/acre)
1
  • Combine with 1.75 to 2.25 kg/ha (700 to 900 g/acre) mancozeb 80%.
  • Apply at 7 to 10 day intervals, starting when plants are 15 cm high.
  • Maximum 10 applications per season.
  • Apply at vine kill with a desiccant, or alone after vine kill at 2.4 L/ha (960 mL/acre). This may prevent late blight infection of tubers during harvest.
M
(inorganic)

Kocide 2000

(copper hydroxide)
 
Used in organics.
0.8 to 1.6 kg/ha
(300 to 350 g/acre)
1
  • Apply at 7 to 10 day intervals, starting when plants are 15 cm high.
  • Apply 2.4 kg/ha (1 kg/acre) at vine kill with a desiccant or just prior to harvest. This may reduce Late Blight infection of tubers during harvest.
  • Can be combined with Manzate DF at 1.75 to 2.25 kg/ha (700 to 900 g/acre).
  • Kocide 2000 (PCP# 27348) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.
M
(inorganic)

Copper Spray

(Fixed Copper)

4.0 kg/ha
(1.6 kg/acre)
1
  • Apply every 7 to 10 days beginning when plants are 10 to 20 cm high, increasing the rate as the vines increase in size.
  • Apply in 1000 L of water per hectare (405 L of water per acre).
  • Maximum 10 applications per season.
  • Do not enter treated area for 48 hours.
M
(inorganic)

Copper Oxy-chloride 50

(copper hydroxide)

4.0 kg/ha
(1.6 kg/acre)
 
Apply in 1000 L/ha (405 L/acre) of water
1
  • Apply every 7 to 10 days beginning when plants are 10 to 20 cm high, increasing the rate as the vines increase in size
  • Maximum 10 applications per season.
  • Do not enter treated area for 48 hours.
M
(inorganic)

Copper 53W

(tri-basic copper sulphate)

3.8 kg/ha
(1.5 kg/acre)
1
  • Apply when plants are 12 to 18 cm high.
  • Repeat at 7 to 10 day intervals.
  • Maximum 10 applications per season.
M
(inorganic)

Cueva

(copper octanoate)

Group M1

Use a 0.5%  to 2%  solution at 470 to 940 L/ha (190 to 380 L/acre) 1
  • For a 0.5% solution, mix 1 part Cueva to 200 parts water.
  • For a 2% solution, mix 1 part Cueva to 50 parts water.
  • Repeat at 7 to 10 day intervals.
  • Repeat at 5 to 7 day intervals following heavy rain or when disease pressure is high.
  • Do not make more than 15 applications per year.
  • Time applications so that 12 hours of dry weather follow application.
  • Do not re-enter treated area for 4 hours.
(biofungicide)

Timorex Gold

(tea tree oil)
 
Used in organics.
2.25 L/ha
(910 mL/acre)
 
Apply in 200 to 400 L/ha (80 to 160 L/acre) of water.
2
  • Suppression only.
  • Apply as a foliar spray until runoff.
  • Repeat using a 7 to 14 day interval.
  • Do not apply with captan or sulphur.
  • Timorex Gold (PCP# 30910) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.

21
(benzamide)

Ranman 400SC

(cyazofamid)
100 to 200 mL/ha
(40 to 80 mL/acre)
7
  • Tank mix with Sylgard 309 at 150 mL/ha (60 mL/acre).
  • Repeat at 7 day intervals.
  • Do not apply more than 6 times per year.
  • Use the high rate for the last 2 or 3 applications prior to dessication.
  • Do not enter treated area for 12 hours.
  • Observe plant back interval of 30 days.

27
(cyamoxanil)

 

M
(dithiocarbamate)

Curzate 60 DF

(cymoxanil)

Plus: 

Manzate DF

(mancozeb)

225 g/ha
(90 g/acre)
 

 

Plus:

1.35 to 1.6 kg/ha
(0.5 to 1.6 kg/acre)

8
  • Apply as a tankmix in 200 to 1000 L/ha (80 to 405 L/acre) of water.
  • Repeat every 5 to 7 days.
  • Do not apply more than 7 times per season.
  • Do not apply within 2 hours of rainfall.
  • Do not re-enter treated area for 24 hours.

29

(pyradinamine)

Allegro 500F

(fluazinam)

400 mL/ha
(160 mL/acre)
14
  • Spray volumes vary with plant growth, see label.
  • Begin applications when plants are 15 to 20 cm tall or when conditions favour disease development.
  • Repeat using a 7 to 10 day interval.
  • Do not make more than 10 applications per year.
  • Do not make more than 3 sequential applications before alternating to a fungicide with a different mode of action.
  • Do not enter treated area for 24 hours.
  • Areas treated may be replanted to potatoes as soon as practical. For other root crops and leafy vegetables, observe a 30 day plant back interval (PBI). For all other crops the PBI is 70 days.

33

(phosphonate)

Confine Extra        

(mono- and di-potassium

salts of phosphorous acid)

Foliar: 
5 to 10 L/ha  
(2.0 to 4.0 L/acre)
 
Apply in 100 L/ha (40 L/acre) of water.
1
  • Suppression only.
  • Do not use on potatoes intended for seed.
  • Repeat using a 7 to 14 day interval.
  • Do not make more than 5 applications per growing season.
  • Tankmixing with pesticide products containing a metal base and/or micronutrients may not be compatible and could potentially cause plant injury.  See label for details.

33

(phosphonate)

Confine Extra        

(mono- and di-potassium

salts of phosphorous acid)

Post harvest:  dilute at a 1:5.13 ratio with water
 
(equivalent to 326 mL product mixed with 1674 mL water to treat 1000 kg potatoes)
N/A
  • Post-harvest storage treatment.
  • Suppression only.
  • Do not use on potatoes intended for seed.
  • Apply 2 L of this solution as a spray to 1000 kg of potatoes prior to storage.
  • Ensure thorough coverage.

33

(phosphonate)

Phostrol

(mono- and dibasic sodium, potassium, and ammonium phosphites)

Foliar: 
2.9 to 11.6 L/ha
(1.2 to 4.7 L/acre)
 
Apply in 200 L/ha (80 L/acre) of water.
 

0

 

 

 

 

  • Apply as a foliar spray on a 7 to 14 day interval.
  • Do not make more than 7 applications in a season when using as a foliar, in-furrow or post-harvest treatment.
  • May be applied as a tankmix with Bravo 500 or Echo 720 or Echo 90DF or Ridomil Gold/Bravo Twin Pack or Dithane F-45 or Dithan DG 75 or Dithan DG Rainshield NT or Gavel 75DF or Penncozeb 75 DF.  Read and follow the use directions including PHI and re-entry interval on the individual product labels.
  • Do not re-enter treated area for 12 hours.

 

33

(phosphonate)

Phostrol

(mono- and dibasic sodium, potassium, and ammonium phosphites)

Post-harvest:
0.42 L water to 1 tonne tubers
N/A
  • Post-harvest storage treatment.
  • Apply directly to tubers.
  • Ensure complete coverage.
  • Do not make more than 7 applications in a season when using as a foliar, in-furrow or post-harvest treatment.
  • Do not re-enter treated area for 12 hours.

33

(phosphonate)

Confine

(mono- and di-potassium

salts of phosphorous acid)

Post-harvest:  dilute at a 1:4.3 ratio with water N/A
  •  Post-harvest storage treatment.
  • Suppression only.
  • Not recommended for use on seed potatoes.
  • Apply 2 L of this solution as a spray to 1000 kg of potatoes prior to storage.
  • Ensure thorough coverage.

33

(phosphonate)

Rampart

(mono- and dipotassium

salts of  phosphorous acid)

Post-harvest:  dilute 190 mL of product in 1 L of water N/A
  • Post-harvest storage treatment.
  • Do not apply more than once per year.
  • Apply as soon as possible after harvest.
  • Prior to storage:  Apply 2 L of solution as a spray rinse to 1000 kg of harvested tubers prior to storage.
  • Stored potatoes:  Inject 2 L of solution per 1000 kg of stored tubers into water used for the post-harvest storage humidification system.

40

(carboxylic acid

amide)

Revus

(mandipropamid)

400 to 600 mL/ha
(160 to 240 mL/acre )
 
Apply in 100 L/ha (40 L/acre) of water

 

14
  • Use a non-ionic adjuvant (0.25% v/v).
  • Repeat at 7 to 10 day intervals.
  • Do not apply more than 4 times per year.
  • May be tank-mixed with Bravo 500. Check Bravo Label for re-entry intervals
  • Do not enter treated area for 12 hours.

40

(carboxylic acid

amide)

Forum

(dimethomorph)

450 mL/ha
(182 mL/acre)
 
For concentrated sprays:
apply in 50 to 100 L/ha (20 to 40 L/acre) of water. 
 
For diluted sprays:
apply in 225 to 1600 L/ha (90 to 645 L/acre) of water.
4
  • Must be tank mixed with either: Polyram DF, Dithane DG Rainshield NT, or Bravo 500 (see labels). Follow the most restrictive applications directions for number of applications, timing, PHI*, plantback interval, re-entry and buffer requirements.
  • Under high level of blight infection apply after topkill to reduce tuber blight.
  • Repeat using a 5 day interval.
  • Do not apply more than 3 times per season.

43

(acylpicolide)

Presidio

(fluopicolide)

220 to 292 mL/ha
(89 to 118 mL/acre)
 
Apply in 200 to 500L/ha (80 to 200 L/acre) of water.
7
  • Tank-mix with a product that has a different mode of action listed in this table for late blight, such as Bravo 500. Follow most restrictive directions including rate, PHI and re-entry interval.
  • Repeat using a 7 to 10 day interval.
  • Do not make more than 4 applications per season.
  • Maximum of 880 mL/ha (356 mL/acre) per season.
  • Do not combine in-furrow/soil applications with foliar applications of Presidio.
  • Do not enter treated area for 12 hours.
  • Also controls pink rot when used in-furrow or as a soil application.  See Pythium Leak and Pink Rot section of this page for details.

45 & 40

(triazolopyrimidylamine/

carboxylic acid amide)

Zampro

(ametoctradin &

dimethomorph)

0.8 to 1.0 L/ha
(300 to 400 mL  /acre)

Apply in 200 L/ha (80 L/acre) of water.
4
  • Repeat at 5 to 10 day intervals.
  • Do not apply more than 3 times per season.
  • Use a spreading/penetrating  adjuvant.
  • For reduction in tuber blight, use the high rate immediately prior to or after vine kill.
  • Do not re-enter for 12 hours.
  • Observe a plantback interval of 30 days for all crops not on the label.
49

Orondis

(oxathiapiprolin)

120 to 350 mL/ha
(49 to 140 mL/acre
 
Apply in 110 L/ha (45 L/acre) of water.
5
  • Repeat at 7 to 14 day intervals.
  • Do not use following a soil application of Orondis.  See Pythium Leak and Pink Rot section of this page for details.
  • Where multiple crop cycles are produced in the same year, do not make more than 6 applications/ha/year.
  • Do not apply more than 1.40 L/ha (570 mL/acre) per season.
  • Do not re-enter treated area for 12 hours.
  • Also suppresses Pink rot. See Pythium Leak and Pink Rot section of this page for details.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI- Canada = Organic Materials Review Institute of Canada

Leaf roll is caused by a virus which overwinters in the tubers and is carried from diseased to healthy plants by green peach aphids. If diseased tubers are planted, lower leaves appear rolled and stiff. Symptoms appear when the plant is about 15 cm high. If infection occurs in the field (current season infection), leaf roll symptoms rarely appear on the lower leaves and may or may not appear on the upper leaves. Current season infection causes net necrosis in the tubers of Russet Burbank and a few other varieties. Tuber necrosis may increase in storage.

Control

  1. Use only certified seed.
  2. Rogue seed fields early and often, including all volunteers (carry plant and seed-piece clear of field and bury if practical).
  3. Do not plant susceptible varieties such as Russet Burbank in fields which have volunteers from the previous year or adjacent to fields with volunteers.
  4. Winter flooding can be used to kill tubers in the field and prevent volunteers in areas with adequate natural flooding and in dyked fields with water control.
  5. If you are growing your own seed, set seed plot away from edge of field.
  6. Control aphids. Early and mid-season varieties should be sprayed, not later than mid-July, to prevent aphid build-up and migration to late potatoes, where they may cause net necrosis in Russet Burbank and some other varieties. Spray all seed potatoes for aphids after mid-July.
  7. Top-kill seed crops early to avoid the fall migration of winged aphids.

The organisms causing leak and pink rot are closely related to late blight but are soil-borne and attack the roots and tubers. Pink rot infects tubers in the soil prior to harvest while leak infection occurs during harvest and handling, especially during warm weather. Affected tubers may appear normal on the outside, but feel soft. If squeezed, liquid oozes out. Internally, the tuber is broken down and dirty-white to gray in colour with a black ring in the case of leak. Tubers infected with pink rot will turn pink after they are cut and exposed to the air.

Control

Land-leveling and drainage to eliminate wet spots and rotation away from fields with a history of pink rot or leak are recommended. Avoid heavy irrigation on dry, hot soil. Ensure tubers have a good skin set before digging. Do not leave tubers on ground in hot sun. During hot weather, dig between midnight and 10 a.m. Pre-cool to 13°C, and specify transit temperature of 13 to 16°C. Prevent injury to tissue. Keep tubers dry and cool during harvest and storage.

If planting into a field with a history of either disease, consult the table below.

Chemical Control of Pythium Leak and Pink Rot

Group Product Rate PHI* Comments

11 & 7

(amide/strobilurin)

Serenade Soil

(QST 713 strain of

dried Bacillus subtilis)

 

Used in organics.

2.7 to 14 L/ha

(1.1 to 5.7 L/acre)
0
  • Suppression of pink rot only.
  • Does not control pythium leak.
  • Serenade Soil (PCP# 30666) is OMRI-Canada listed.  Check with your certification body before using in an organic operation.

In-Furrow Application:

  • Apply in a narrow band with the spray directed at the seed and surrounding soil  before covering the seed or seed piece.

Post-plant applications:

  • After crop germination, additional applications may be made to the soil as a drench or spray directed towards the base of the plant.
  • Irrigate to move material into the seed or root zone within 24 hours.
  • Repeat at 21 to 28 day intervals.

4 M (phenylamide/

chloronitrile)

Ridomil Gold/Bravo Twin Pak

(metalaxyl-M / chlorothalonil)

Note:  no longer produced.

1 jug per 4 ha
(1 jug per 10 acres)
N/A
  • Suppression only.
  • Do not use more than 3 times per season
  • Use in 225 – 1600 L/ha (90-640 L/acre) of water at 275 KPa (40 psi).
  • Apply when the largest tubers are nickel-sized and repeat at 10 to 14 day intervals for up to two more treatments. Check label for details.
  • Apply a contact fungicide for late blight 5-7 days after each Ridomil application.
  • Do not tank mix with a top-killer.

4 M (phenylamide/

chloronitrile)

Ridomil Gold MZ 68WP

(metalaxyl-M/ mancozeb)

2.5 kg/ha
(1.0 kg/acre)
N/A
  • Suppression only.
  • Do not use more than 3 times per season
  • Use in 225 – 1600 L/ha (90-640 L/acre) of water at 275 KPa (40 psi).
  • Apply when the largest tubers are nickel-sized and repeat at 10 to 14 day intervals for up to two more treatments. Check label for details.
  • Apply a contact fungicide for late blight 5-7 days after each Ridomil application.
  • Do not tank mix with a top-killer.
4 (phenylamide)

Ridomil Gold 480 SL

(metalaxyl-M)

4 to 6 mL of product per 100 m of row 90
  • Pink rot suppression only.
  • Does not control pythium leak.
  • Apply 4 ml per 100 m of row directly over the seed pieces in furrow as a 15-20 cm band prior to row closure.
  • Apply in 30 L/ha (12 L/acre) of water.
  • Apply only one time per season.
  • Do not enter treated area for 12 hours.
  • Observe a plant back interval of 30 days.
  • For control of Colorado potato beetle, potato leafhopper and aphids, tankmix with Actara 240SC (see label for details).
4 (phenylamide)

Orondis Gold B 480SL

(metalaxyl-M and S-isomer)

In-furrow:

4 mL per 100 m of row

Apply in 30 L/ha (12 L/acre) of water
N/A
  • Suppression only.
  • Apply in-furrow so the spray is directed as a 15 to 20 cm band just before the seed is covered.
  • Do not apply more than one time per season.
  • Do not follow with any applications of Orondis Gold B 480SL fungicide beyond the planting stage.
  • Do not re-enter for 12 hours.

33

(phosphonates)

Phostrol

(mono- and dibasic sodium, potassium, and ammonium phosphites

In-furrow: 
5.8 to 11.6 L/ha
(2.3 to 4.7 L/acre)
 
Apply in 30 L/ha (12 L/acre) of water.
 
 
N/A
  • Suppression of pink rot only.
  • Does not control pythium leak.
  • Apply in a band at planting over the seed pieces prior to row closure.
  • May be applied as a tankmix with Ridomil Gold 480 SL.  Read and follow the use directions on the individual product labels.  Check PHI on Ridomil 480 SL label.
  • Do not re-enter treated area for 12 hours.

 

33

(phosphonates)

Phostrol

(mono- and dibasic sodium, potassium, and ammonium phosphites

Foliar: 
5.8 to 11.6 L/ha
(2.3 to 4.7 L/acre)
 
Apply in 200 L/ha (80 L/acre) of water.
0
  • Suppression of pink rot only.
  • Does not control pythium leak.
  • Apply as a foliar spray on a 7 to 14 day interval.
  • Do not make more than 7 applications in a season.
  • May be applied as a tankmix with Ridomil gold MZ 68WP or Ridomil Gold /Bravo Twin Pack.  Read and follow the use directions on the individual product labels.

33

(phosphonate)

Phostrol

(mono- and dibasic sodium, potassium, and ammonium phosphites)

Post-harvest:

0.42 L water to 1 tonne tubers
N/A
  • Does not control pythium leak.
  • Post-harvest storage treatment.
  • Apply directly to tubers.
  • Ensure complete coverage.
  • Do not make more than 7 applications in a season when using as a foliar, in-furrow or post-harvest treatment.
  • Do not re-enter treated area for 12 hours.

(phosphonate)

Confine Extra        

(mono- and di-potassium

salts of phosphorous acid)

Foliar: 

5 to 10 L/ha  

(2.0 to 4.0 L/acre)

 

Apply in 100 L/ha (40 L/acre) of water.
1
  • Suppression of pink rot only.
  • Does not control pythium leak.​
  • Do not use on potatoes intended for seed.
  • Repeat using a 7 to 14 day interval.
  • Do not make more than 5 applications per growing season.
  • Tankmixing with pesticide products containing a metal base and/or micronutrients may not be compatible and could potentially cause plant injury.  See label for details.

33

(phosphonate)

Rampart

(mono- and dipotassium

salts of  phosphorous acid)
Post-harvest:  dilute 190 mL of product in 1 L of water N/A
  • Post-harvest storage treatment.
  • Does not control pythium leak.
  • Do not apply more than once per year.
  • Apply as soon as possible after harvest.
  • Prior to storage:  Apply 2 L of solution as a spray rinse to 1000 kg of harvested tubers prior to storage.
  • Stored potatoes:  Inject 2 L of solution per 1000 kg of stored tubers into water used for the post-harvest storage humidification system.

43

(acylpicolide)

Presidio

(fluopicolide)

292 mL/ha
(118 mL/acre)
 
In-furrow:  
Apply in 50 to 100 L/ha (20 to 40 L/acre) of water.
 
Soil application:  
Apply in 200 to 400 L/ha (80 to 160 L/acre) of water.
30
  • Does not control pythium leak.
  • Tank-mix with a product that has a different mode of action listed in this table for pink rot, such as Ridomil Gold 480 SL or Phostrol. Follow most restrictive directions including rate, PHI and re-entry interval.
  • Apply in-furrow using a 15 to 20 cm band directly over the seed piece, or in the furrow where the seed piece is to be dropped, prior to covering with soil.
  • Repeat between hilling and tuber initiation, as either a banded spray directly to the soil at the base of plants, or as a broadcast spray.
  • Do not combine in-furrow/soil applications with foliar applications of Presidio.
  • Do not make more than 2 applications of Presidio per season.
  • Maximum of 880 mL/ha (356 mL/acre) per season.
  • Do not enter treated area for 12 hours.
49

Orondis

(oxathiapiprolin)

In-furrow:
6.4 ml/100 m row length
 
Apply in 40 L/ha (16 L/ac) of water
N/A
  • Pink rot suppression only.
  • Does not control pythium leak.
  • Apply once as an in-furrow spray at planting.
  • Direct the spray into the furrow as a 15 to 20 cm band just before the seed is covered.
  • Do not follow with foliar applications of Orondis (see Late Blight Only section of this table).
  • Do not apply more than 1.40 L/ha (570 mL/acre).
  • Do not re-enter treated area for 12 hours.
49

Orondis Gold A 200SC

(oxathiapiprolin)

In-furrow:

3.2 mL per 100 m of row

Apply in 40 L/ha (16 L/acre) of water
N/A
  • Suppression of pink rot only.
  • Does not control pythium leak.
  • Do not apply in greenhouses.
  • Apply in-furrow so the spray is directed as a 15 to 20 cm band just before the seed is covered.
  • Do not apply more than one time per season.
  • Do not follow with foliar applications of Orondis fungicides or any other Group 49 -containing product.
  • Observe a plantback interval of 180 days for all legume crops except succulent peas.
  • Do not re-enter for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

Mosaic is caused by one or more of potato viruses X, S, Y, M and A. Potato virus Y exists in different strains. PVY (o) occurs in Western Canada. PVY (n), which does not cause symptoms on potato but is damaging to tobacco, occurs in other parts of the world. Leaves of mosaic-infected plants are mottled, may be wrinkled and distorted, or have veinal necrosis. Plants are stunted and yields are reduced.

Control

Use certified seed. Rogue early and often as for leaf roll. Control aphids.

The northern root-knot nematode is a minor pest of potato in some areas of British Columbia. The Columbia root-knot nematode, newly discovered in the United States and established in the Lynden area in Washington State, is apparently not present in Canada. It is a serious pest of potatoes in the Columbia Basin and other areas of the Pacific Northwest. The Columbia root-knot nematode can reproduce faster and at lower temperatures than the northern root-knot nematode, and is considered a potentially serious threat to the B.C. potato industry. Quarantine regulations are in effect to avoid entry of infected seed potatoes and other plant products, as this nematode is spread mainly in seed potatoes and infested soil.

Small protuberances can be detected on roots and tubers of infected plants. High populations cause wilting and, premature senescence of foliage, and disfiguration of tubers. Nematode analysis of soil and root samples is necessary for the diagnosis. If root-knot is suspected, submit a root and/or tuber sample to the Plant Health Laboratory. To have a soil sample tested, contact a nematode testing service to determine when and how to collect the sample.

Control

  1. Use seed potatoes certified free of root-knot nematode.
  2. Destroy all culls and volunteers from previous potato crops.
  3. Where the northern root-knot nematode is present, rotation with small grains, grasses and corn is recommended, while alfalfa should be avoided.
  4. Fumigate in late summer with Vapam according to label directions.
Chemical Control of Root-knot Nematodes
Group Product Rate PHI* Comments

7
(carboxamide)

succinyl dehydrogenase inhibitor (SDHI) class

Velum Prime

(fluopyram)

500 mL/ha 

or

4.5 mL of product per 100 m of row (based on 90 cm row spacing)
N/A
  • Suppression of Root lesion (Pratylenchus spp.) and Root knot (Meloidogyne spp.) nematodes.
  • Apply in 50 to 150 L/ha (20 to 60 L/acre of water.
  • Apply in a 10 to 15 cm band in-furrow at planting, directing the spray to the seed and soil just before the seed is covered.
  • Use a another mode of action or group number for the first foliar fungicide application.
  • Observe a plant back interval of 14 days for alfalfa.
  • Do not re-enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

The organism is present in the soil or on the seed and causes round or oval, raised, corky spots or thick, irregular roughening/russetting on the surface of tubers.

Control

Practise long rotations with small grains, grasses and corn. Plow under green cover crops. Apply acid-producing fertilizers and limited quantities of sulfur, 225 to 325 kg/ha (90 to 130 kg/acre). Avoid alkaline-producing soil amendments like lime, ashes or nitrate of soda. Manure, especially poultry manure, should be applied in the fall, not in the spring just prior to planting. Maintain good soil moisture at time of tuber formation. Plant clean seed.

Silver scurf is a fungal disease transmitted largely by infected seed pieces. Soil transmission may occur to a limited extent. Potato is the only known host. Infection takes place through the lenticels and skin before tubers are dug. Only skin tissue is affected. Extensive lesion enlargement and some new infections may occur in storages in which temperatures exceed 3°C and relative humidity is at least 90%. Symptoms consist of silvery blotches on the skin and there may be considerable loss of colour on red varieties.

Control

  1. Avoid planting infected seed pieces.
  2. Avoid planting potatoes in fields where volunteers are likely to grow.
  3. Harvest tubers as soon as they are mature.
  4. If there are no resistant strains of the fungus present, seed-piece treatments (eg. Maxim PSP and Senator PSPT) and the Mertect treatment recommended under Fusarium Rot (this section) may be of some value. These treatments will be of no value if resistant strains are present. See Potato Seed Piece Treatments section of this page for more information.
  5. For suppression in table and processing potatoes, use Stadium (azoxystrobin/ difnoconazole/ fludioxonil) as a post-harvest treatment.  See Fusarium section for rate and precautions.  Do not use on seed potatoes.  Do not make more than 1 post-harvest application to the tubers.

StorOx (formerly called Oxidate) is registered for control of silver scurf in storage. Follow label precautions carefully to avoid operator and environmental hazards (see Storage section, this chapter, for more details).

Chemical Control of Silver Scurf

Group Product Rate PHI* Comments

7

(carboxamide) (SDHI)

Aprovia

(benzovindiflupyr)

500 to 750 mL/ha
(200 to 300 mL/acre) 
 
or
 
4.5 to 6.8 mL per 100 m of row (based on 90 cm row spacing)
 
Apply in 50 to 150 L/ha (20 to 60 L/acre) of water
N/A
  • Suppression only.
  • Apply as an in-furrow spray, directing the spray into the furrow as a 15 to 20 cm band just before the seed is covered.
  • Do not aply more than 750 mL/ha (300 mL/acre) per application.
  • Do not apply more than 100 g a.i./ha (40 g a.i./acre) of benzovindiflupyr-containing products on potato crops per season if an in-furrow application is made.
  • Observe a plantback interval of 6 months for crops not listed.
  • Do not re-enter treated area for 12 hours.
11
(strobilurin)

Quadris F

(axosystrobin)

4 to 6 mL of product per 100m of row 90
  • Apply in 50 to 140 L/ha (20 to 55 L/acre of water.
  • Apply once as an in-furrow spray as a 15 to 20 cm band just before the seed is covered.
  • Observe a plant back interval of 30 days for potatoes (root crops).

11 & 7

(amide/strobilurin)

Elatus

(benzovindiflupyr/

azoxystrobin)

See rate conversion chart of label for rates per 100 m row.
 
Apply in 50 to 150 L/ha (20 to 60 L/acre) of water.
N/A
  • Make an in-furrow application at planting.
  • Do not apply more than 1.5 kg/ha (0.6 kg/acre) per season.
  • Observe a plantback interval of 6 months for crops not listed.
  • Also controls black dot when used as a foliar spray.  Check label.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI- Canada = Organic Materials Review Institute of Canada

The fungus survives in the soil or infected plant parts. It invades through the roots causing premature yellowing and death of the vine. Yields can be greatly reduced when disease is severe. It is more prevalent in the Interior.

Control

  1. Practice crop rotation, avoiding tomatoes, peppers, eggplants and melons.
  2. High rates of nitrogen fertilizer delay the appearance of symptoms.
  3. Soil fumigation is used in Washington but is usually not warranted nor would it be very effective in coastal B.C. It may be necessary for continued potato production on some of the lighter soils in the B.C. Interior.
  4. Windrowing and burning infected tops promptly after harvest will reduce inoculum carryover but may encourage scab in succeeding potato crops.
  5. Senator seed piece treatment is registered for verticillum wilt. See Potatoes Seed Piece Treatments section of this page.
Chemical Control of Verticillium Wilt
Group Product Rate PHI* Comments

7

(carboxamide) (SDHI)

Aprovia

(benzovindiflupyr)

750 mL/ha

(300 mL/acre) 

or

6.8 mL per 100 m of row (based on 90 cm row spacing)

Apply in 50 to 150 L/ha (20 to 60 L/acre) of water
N/A
  • Suppression only.
  • Apply as an in-furrow spray, directing the spray into the furrow as a 15 to 20 cm band just before the seed is covered.
  • Do not apply more than 750 mL/ha (300 mL/acre) per application.
  • Do not apply more than 100 g a.i./ha (40 g a.i./acre) of benzovindiflupyr-containing products on potato crops per season if an in-furrow application is made.
  • Observe a plantback interval of 6 months for crops not listed.
  • Do not re-enter treated area for 12 hours.
         

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

OMRI- Canada = Organic Materials Review Institute of Canada

 

Potato Seed Piece Treatments

Chemical Control of Fusarium Seed Piece Decay

Group Product Rate Comments
M

Tuberseal

(mancozeb)
500 g per 100 kg of seed
(4.5 kg per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces with dust.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If planting of cut seed is delayed beyond 2 days after treating, seed should be stored in open crates to allow air drying until dry before bagging or loose piling.
  • Do not use surplus treated seed pieces for food or feed.
M

Potato ST16

(mancozeb)
500 g per 100 kg of seed
(4.5 kg per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces with dust.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If planting of cut seed is delayed beyond 2 days after treating, seed should be stored in open crates to allow air drying until dry before bagging or loose piling.
  • Do not use surplus treated seed pieces for food or feed.
M

MancoPlus

(mancozeb)
500 g per 100 kg of seed
(4.5 kg per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces with dust.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If planting of cut seed is delayed beyond 2 days after treating, seed should be stored in open crates to allow air drying until dry before bagging or loose piling.
  • Do not use surplus treated seed pieces for food or feed.

Chemical Control of Black Scurf, Silver Scurf and Fusarium Dry Rot

Group Product Rate Comments
1

Senator PSPT

(thiophanate-methyl)
500 g per 100 kg of seed
(4.5 kg per ton of seed)
  • Does not control Black Scurf.
  • Also controls Verticillium Wilt.
  • For optimum control of Silver Scurf, ensure that seed tubers are completely free of soil.
  • Thoroughly coat the surface of whole or cut seed pieces.
  • Cut seed should be treated witin 6 hours of cutting.
  • If planting is delayed more than 1 to 2 days, treated seed should be stored for 2 or 3 days in open crates before bagging.
  • Do not use if seed was produced using Senator.
M3 & 12

Maxim MZ PSP

(fludioxonil & mancozeb)
500 g per 100 kg of seed
(4.5 kg per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If cut seed needs to be stored or held for a few days, ensure adequate cool air movement throught the pile at relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8m in height.
  • Store cut seed at or below 7ºC.
  • Do not use if seed was produced using Maxim.
  • Maxim PSP and Maxim D may be tank-mixed with Actara 240 SC to control CPB, aphids and leafhopper. See labels for details.  Obey the most restrictive label precautions.
  • Do not use an open cab tractor when planting seed treated with Maxim D.
12

Maxim PSP

(fludioxonil)
5.2 mL per 100 kg of seed
(47.1 mL per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If cut seed needs to be stored or held for a few days, ensure adequate cool air movement throught the pile at relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8m in height.
  • Store cut seed at or below 7ºC.
  • Do not use if seed was produced using Maxim.
  • Maxim PSP and Maxim D may be tank-mixed with Actara 240 SC to control CPB, aphids and leafhopper. See labels for details.  Obey the most restrictive label precautions.
  • Do not use an open cab tractor when planting seed treated with Maxim D.
12 & 3

Maxim D

(fludioxonil & difenoconazole)
130 mL per 100 kg of seed
(1.2 L per ton of seed)
  • Thoroughly coat the surface of whole or cut seed pieces.
  • If treated whole seed is cut, make a second application to protect the cut surface.
  • Plant as soon as possible after treating.
  • If cut seed needs to be stored or held for a few days, ensure adequate cool air movement throught the pile at relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8m in height.
  • Store cut seed at or below 7ºC.
  • Do not use if seed was produced using Maxim.
  • Maxim PSP and Maxim D may be tank-mixed with Actara 240 SC to control CPB, aphids and leafhopper. See labels for details.  Obey the most restrictive label precautions.
  • Do not use an open cab tractor when planting seed treated with Maxim D.
 

Heads Up

(Saponins of Chenopodium quinoa)
1 g per L of water

1 Litre of solutions per 100 to 264 kg of seed
  • Suppression only.
  • Apply to whole or cut seed.
  • Must be applied to germinating seed potatoes from peeking to full sprout, but before green leaves appear.
  • Ensure that the product is thoroughly dissolved in solution and agitate prior to application.
  • Thoroughly coat seed.
  • Do not store treated seed beyond planting time.
  • Do not use treated seed for animal feed or for food or oil purposes.
  • Treat seed in a well-ventilated area.
3 & 7

Emesto Silver

(penflufen & prothioconzole)
20 mL/100 kg of seed
  • Also controls Seedborne Rhizoctonia Stem and Stolon Canker.
  • Apply 150 mL of slurry/100 kg of seed.
  • Apply to whole or cut seed.
  • Treat seed immediately after cutting.
  • Agitate slurry solution as needed.
  • Thoroughly coat seed.
  • Periodically clean and sanitize all surfaces which may come in contact with cut seed.
  • As part of seed-treating and cutting, apply an absorbent ingredient to improve suberization.
  • Plant as soon as possible after cutting and treating.
  • If cut seed needs to be stored for a few days, ensure adequate cool air flow through the pile at a relative humidity of 85-90%. Store at below 7°C, and do not pile above 1.8 m high.
  • Cover treated seed when transporting.
  • Do not use treated seed for food, feed or fodder.
  • Treat seed in a well-ventilated area.
  • For suppression of wireworm, Emesto Silver can be tankmixed with Titan ST. Follow the most restrictive label precautions.
3, 7 & 40

Vibrance Ultra Potato

(sedaxane/ difenoconazole/ mandipropamid)

32 mL/ 100 kg of seed

  • Also provides preventative control of seed-borne late blight.
  • Also suppresses pink rot.
  • The rate will deliver 2.5 g ai/100 kg seed of difenoconozale and sedaxane, and 5.0 g ai/100 kg seed of mandipropamid.
  • Do not apply more than 600 g mandipropamide per ha per year.
  • Check Revus label for maximum number of foliar applications allowed following the use of Vibrance Ultra Potato PSPT
  • Do not use treated seed for food, feed or oil processing.
  • Keep treated seed away from animals. 
  • Treat seed in a well-ventilated area.
  • For control of CPB, aphids and potato leafhopper, Vibrance Ultra Potato may be tank mixed with Actara 240 SC.  Follow the most restrictive label precautions.

3 & 12 fungicides

&

4 insecticide

Cruiser Maxx Potato Extreme

(fludioxonil/  difenoconazole/ thiamethoxam)
20 mL per 100 kg of seed
  • Also controls seed-borne stem and stolon canker, Colorado potato beetle, aphids and potato leafhopper.
  • Suppression only for black scurf.
  • For control of black scurf, may be tank-mixed with Maxim PSP.  See label for rate.
  • Apply using standard closed system slurry seed treatment equipment.
  • Ensure uniform coverage of seed.
  • Apply only in areas with adequate ventilation.
  • If soil conditions are ideal, plant immediately afer application.
  • If cutting, treating and storing is necessary; apply an inert dust to improve suberization.
  • If storing treated seed, ensure adequate cool air (7 to 10 °C) movement through the pile and relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8 m in height.
  • Do not store treated potatoes for over 2 weeks.
  • Do not use on excessively sprouted seed.
  • Do not plant more than 128,700 kg of treated seed per day.  See label for Planting Rate/Planted Area Chart.
  • Toxic to bees.
  • Do not follow with an in-furrow or subsequent foliar application of a group 4 insecticide.
  • Observe a plantback interval of 120 days for crops not listed.
Chemical Control of Late Blight
Group Product Rate Comments
3, 7 & 40

Vibrance Ultra Potato

(sedaxane/ difenoconazole/ mandipropamid)
32 mL/ 100 kg of seed
  • Seed-borne control (preventative).
  • The rate will deliver 2.5 g ai/100 kg seed of difenoconozale and sedaxane, and 5.0 g ai/100 kg seed of mandipropamid.
  • Do not apply more than 600 g mandipropamid per ha per year (243 g per ac per year).
  • If following with a foliar application of heck Revus label rate chart for maximum number of foliar applications of Revus allowed following the use of Vibrance Ultra Potato PSPT
  • Do not use treated seed for food, feed or oil processing.
  • Keep treated seed away from animals. 
  • Treat seed in a well-ventilated area.
  • Vibrance Ultra Potato may be tank-mixed with Actara 240 SC to control Colorado Potato Beetle. Obey the most restrictive label precautions.
40

Revus

(mandipropamid)
13 - 26 mL/ 100 kg of seed
  • Seed-borne control (preventative).
  • Apply using a closed treatment system.
  • Add sufficient water when making slurry that will allow for thorough coverage of seed.
  • The rate will deliver 3.25 to 6.5 g ai/100 kg of seed.
  • Do not apply more than 600 g mandipropamid per ha per year (243 g per ac per year).
  • If following with a foliar fungicide application, do not apply a group 40 fungicide as the first application of the season.
  • Check label rate chart for maximum number of foliar applications of Revus following a seed-piece treatment of mandipropamid. 
  • Observe a plantback interval of 30 days for crops not listed.
  • Do not re-enter treated area for 12 hours.

Chemical Control of Aphids, Colorado Potato Beetle (CPB), Flea Beetle (overwintering adults), Leafhoppers

Group Product Rate Comments

Alias 240 SC

(imidacloprid)
26 to 39 mL per 100 kg of seed

Dilute with no more than 3 parts water to 1 part product
  • Provides early-season control of overwintering adult flea beetle and aphids.
  • See label for mixing instructions to prepare spray.
  • Apply only in adequately ventilated area.
  • Apply to seed pieces using a shielded spray system.
  • Good coverage of seed piece is required.
  • Do not follow with an in-furrow or any subsequent foliar applications of imidacloprid or other group 4 insecticide.
  • Do not apply more than 1.165 L/ha (0.668 L/acre) per year (see label for seeding rates).
  • Observe plant back interval of 9 months for peas and beans, 30 days for cereal grains and 12 months for all other crops.
  • If cover crop is planted after harvest, do not use for feed.
  • Do not plant treated seed when rainfall is forecast for the next 48 hours.
4

Actara 240 SC

(thiamethoxam)
See label for rate per 100 kg of seed.
  • Does not control flea beetle.
  • Rates used are based on the seeding rate.  See label for Rate Conversion Chart.
  • See label for mixing instructions.
  • Deliver at a dluted volume of 263 mL/100 kg of seed.
  • Do not add excess water to the cut seed.
  • Apply only in adequately ventilated area.
  • If it is necessary to store treated seed, ensure adequate cool air movement through the pile and relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8 m in height.
  • Store cut seed at or below 7 °C.
  • Do not follow with an in-furrow or any subsequent foliar applications of thiamethoxam or other group 4 insecticide.
  • See label for plantback interval.
  • Can also be applied in-furrow and as a foliar treatment.  See Potatoes Insect Management tables for details.
4

Titan ST

(clothianidin)
10.4 to 20.8 mL per 100 kg of seed
(94.1 to 188.7 mL per ton of seed)
  • Apply only in areas with adequate ventilation.
  • Apply as a diluted spray onto seed using a shielded spray system.
  • Good coverage of seed pieces is required.
  • Do not dilute with any more than 6 parts water to 1 part Titan ST insecticide.
  • Plant as soon as possible after cutting and treating.
  • Do not use treated seed for food or feed.
  • Observe a one year plant back interval (PBI) for leafy, root and tuber vegetables (except for potatoes). A 30 day PBI is required for cereal grains and grasses.
  • Do not make a subsequent application of a Group 4 insecticide following this seed treatment application.
28

Verimark

(cyantraniliprole)
45 mL per 100 kg of seed pieces
 
OR:
 
1000 mL/ha (405 mL/acre) based on 2200 kg/ha (890 kg/acre) planting rate
  • Controls CPB only.
  • Ensure adequate ventilation in application area.
  • Use only a closed treatment system.
  • Good coverage of seed-piece is required for optimal control.
  • Follow treatment with an application of a fungicide potato seed treatment or inert dust.
  • Do not follow seed treatment with any subsequent applications of a group 28 insecticide (in-furrow, soil or foliar). 
  • Do not use open cab planting equipment when planting treated potato seed pieces.
  • Do not exceed more than 1.5 L/ha (0.6 L/acre) per season.
  • Can also be applied in-furrow.  See Potatoes Insect Management tables for details.
28

Fortenza

(cyantraniliprole)
10 to 22.5 mL per 100 kg of seed pieces
  • Controls CPB only.
  • Ensure adequate ventilation in application area.
  • Use only a closed treatment system.
  • Good coverage of seed-piece is required for optimal control.
  • Do not add excess water to cut seed.
  • Avoid treating excessively sprouted seed.
  • Follow treatment with a dust/talc treatment to improve suberization.
  • If it is necessary to store treated seed, ensure adequate cool air movement through the pile and relative humidity of 85 to 90%.
  • Do not pile cut and treated seed above 1.8 m in height.
  • Store cut seed at or below 7 °C.
  • Do not follow seed treatment with any subsequent applications of a group 28 insecticide (in-furrow, soil or foliar). 
  • Do not use open cab planting equipment when planting.
  • Toxic to bees.  Minimize dust exposure to pollinators during planting.

Chemical Control of Wireworms

Group Product Rate Comments

Titan ST

(clothianidin)
20.8 mL per 100 kg of seed
(188.7 mL per ton of seed)
  • Damage suppression only.
  • Apply only in areas with adequate ventilation.
  • Apply as a diluted spray onto seed using a shielded spray system.
  • Good coverage of seed pieces is required.
  • Do not dilute with any more than 6 parts water to 1 part Titan ST insecticide.
  • Plant as soon as possible after cutting and treating.
  • Do not use treated seed for food or feed.
  • Observe a one year plant back interval (PBI) for leafy, root and tuber vegetables (except for potatoes). A 30 day PBI is required for cereal grains and grasses.
  • Do not make a subsequent application of a Group 4 insecticide following this seed treatment application.