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.
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.
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).
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 |
|
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
|
|
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.
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)
|
|
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)
|
|
Aim EC(carfentrazone-ethyl) |
233 to 350 mL/ha Apply in 100 to 200 L/ha (40 to 80 L/acre) of water |
|
Beloukha(500 g/L Pelargonic acid) Group 26 |
16 to 22 L/ha |
|
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).
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 |
|
Eptam 8-E(EPTC) Sencor 75 DF or TriCor 75 DF or (metribuzin)
(Interior BC)
Or Sencor 75 DF or TriCor 75 DF or (metribuzin)
(Coastal BC)
|
4.25 to 5.5 L/ha
PLUS:
Or |
60 |
|
Dual Magnum II(s-metolachlor) Sencor 75 DF or TriCor 75 DF (metribuzin)
(Coastal BC) |
1.25 to 1.75 L/ha
PLUS: 0.75 to 1.5 kg/ha |
60 |
|
*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).
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 |
|
Sencor 75 DF or
Tricor 75 DF or
Sencor Solu-Pak
(metribuzin) (Coastal BC) |
0.55 to 1.5 kg/ha |
60 |
|
Dual Magnum II(s-metolachlor) TriCor 75 DF
(metribuzin)
|
1.25 to 1.75 L/ha PLUS: |
60 |
|
Chateau(flumioxazin) |
105 g/ha (42 g/acre) |
N/A |
|
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:
Medium and fine-textured soils rate:
All soils:
|
Frontier Max(dimethenamid-P)
Group 15 |
*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).
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
Or |
90 |
|
*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).
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 |
|
Venture L(fluazifop-p-butyl) |
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 |
|
Excel Super(fenoxaprop-p-ethyl) |
670 mL/ha (270 mL/acre) Apply in at least 110 L/ha (45 L/acre) of water at 275 kPa. |
35 |
|
Centurion /Select(clethodim) |
Annual Grasses: 190 mL/ha (77 mL/acre) Quackgrass: 380 mL/ha (150 mL/acre) |
60 |
|
Arrow 240 EC(clethodim) |
Annual Grasses: 190 mL/ha (77 mL/acre) Quackgrass: 380 mL/ha(150 mL/acre) |
60 |
|
Prism 25 DF(rimsulfuron) |
60 g/ha
PLUS |
30 |
|
Aim EC(carfentrazone-ethyl) Group 14 |
37 to 117 mL/ha |
7 |
|
*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.
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 |
|
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 |
|
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 |
|
Imidan 50-WP Instapak(phosmet)
Group 1A
|
2.25 kg/ha
(910 g/acre)
|
7 |
|
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 |
|
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 |
|
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 |
|
Cygon 480/ Lagon 480 E(dimethoate)
Group 1B
|
0.55 to 1.1 L/ha |
7 |
|
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 |
|
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 |
|
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 |
|
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 |
|
Admire 240F/ Alias 240 SC(imidacloprid)
Group 4
|
Foliar application:
200 mL/ha
(80 mL/acre)
|
7 |
|
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 |
|
Actara 240SC(thiamethoxam)
Group 4
|
Foliar application:
109 mL/ha (44 mL/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
Actara 25WG(thiamethoxam)
Group 4
|
Foliar application:
105 g/ha (42 g/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
Clutch 50 WDG(clothianidin)
Group 4A
|
Foliar application:
70 to 105 g/ha (28 to 42 g/acre)
|
14 |
|
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 |
|
Twinguard(sulfloxaflor & spinetoram)
Groups 4C & 5
|
200 g/ha
(80 g/acre) Apply in 100 L/ha (40 L/acre) of water
|
7 |
|
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 |
|
Fulfill 50WG(pymetrozine)
Group 9B
|
193 g/ha
(78 g/acre) Apply in at least 100L/ha (40 L/acre) of water
|
14 |
|
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 |
|
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 |
|
Versys(afidopyropen) Group 9D |
100 mL/ha (40 mL/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
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 |
|
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 |
|
*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.
Product | Rate | PHI* | Comments |
---|---|---|---|
Imidan 50-WP Instapak(phosmet)
Group 1A
|
2.25 kg/ha
(900 g/acre)
|
7 |
|
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 |
|
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 |
|
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 |
|
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 |
|
Admire 240F/ Alias 240 SC(imidacloprid)
Group 4
|
Foliar application:
200 mL/ha
(80 mL/acre)
|
7 |
|
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 |
|
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
|
|
Actara 240SC(thiamethoxam)
Group 4
|
Foliar application:
109 mL/ha (44 mL/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
Actara 25WG(thiamethoxam)
Group 4
|
Foliar application:
105 g/ha (42 g/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
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 |
|
Clutch 50 WDG(clothianidin)
Group 4A
|
Foliar application:
70 to 105 g/ha (28 to 42 g/acre)
|
14 |
|
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 |
|
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 |
|
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 |
|
Entrust 80(spinosad)
Group 5
Used in organics
|
50 to 100 g/ha (20 to 40 g/acre) |
7 |
|
Entrust(spinosad)
Group 5
Used in organics
|
167 to 334 mL/ha
(68 to 135 mL/acre)
|
7 |
|
Success(spinosad)
Group 5
|
83 to 167 ml/ha
(34 to 68 ml/acre)
|
7 |
|
Delegate(spinetoram)
Group 5
|
160 to 240 g/ha (65 to 98 g/acre) |
7 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
Sevin XLR(carbaryl)
Group 1A
|
1.25 L/ha
(500 mL/acre)
|
7 |
|
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 |
|
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 |
|
Matador 120EC/ Silencer 120EC(lambda-cyhalothrin)
Group 3
|
83 to 125 mL/ha (34 to 51 mL/acre)
|
7 |
|
Pounce EC(permethrin)
|
180 to 260 mL/ha
(70 to 105 mL/acre)
|
1 |
|
Perm-Up EC(permethrin)
Group 3
|
180 to 260 mL/ha
(70 to 105 mL/acre)
|
1 |
|
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 |
|
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 |
|
Pyrinex 480 EC(chloropyrifos)
Group 1B
|
1.0 L/ha
(400 mL/acre)
|
7 |
|
*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.
Product | Rate | PHI* | Comments |
---|---|---|---|
Imidan 50-WP Instapak(phosmet)
Group 1A
|
2.25 kg/ha
(900 g/acre)
|
7 |
|
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 |
|
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 |
|
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 |
|
Admire 240F/ Alias 240 SC(imidacloprid)
Group 4
|
Foliar application:
200 mL/ha
(80 mL/acre)
|
7 |
|
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 |
|
Sevin XLR(carbaryl)
Group 1A
|
2.5 L/ha
(1.0 L/acre)
|
7 |
|
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 |
|
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 |
|
Matador 120EC/ Silencer 120EC(lambda-cyhalothrin)
Group 3
|
83 mL/ha
(34 mL/acre)
|
7 |
|
Pounce EC(permethrin)
|
180 to 260 mL/ha
(70 to 105 mL/acre)
|
1 |
|
Perm-Up EC(permethrin)
Group 3
|
180 to 260 mL/ha
(70 to 105 mL/acre)
|
1 |
|
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 |
|
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 |
|
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 |
|
Entrust SC(spinosad)
Group 5
Used in organics
|
334 mL/ha
(135 mL/acre)
|
7 |
|
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 |
|
*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.
Product | Rate | PHI* | Comments |
---|---|---|---|
Imidan 50-WP Instapak(phosmet)
Group 1A
|
2.25 kg/ha
(900 g/acre)
|
7 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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 |
|
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
|
|
Actara 240SC(thiamethoxam)
Group 4
|
Foliar application: 109 mL/ha
(44 mL/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
Actara 25WG(thiamethoxam)
Group 4
|
Foliar application:
105 g/ha (42 g/acre) Apply in 100 L/ha (40 L/acre) of water |
7 |
|
Clutch 50 WDG(clothianidin)
Group 4A
|
Foliar application: 70 to 105 g/ha (28 to 42 g/acre) |
14 |
|
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 |
|
Lagon 480 E(dimethoate)
Group 1B
|
0.55 to 1.1 L/ha Apply in 200 to 300 L/ha (80 to 120 L/acre) of water |
7 |
|
Sevin XLR(carbaryl)
Group 1A
|
2.5 L/ha
(1.0 L/acre)
|
7 |
|
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 |
|
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 |
|
Matador 120EC/ Silencer 120EC(lambda-cyhalothrin)
Group 3
|
83 mL/ha
(34 mL/acre)
|
7 |
|
Pounce EC(permethrin)
|
180 to 260 mL/ha
(70 to 105 mL/acre)
|
1 |
|
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 |
|
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 |
|
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 |
|
*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.
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 |
|
Entrust SC(spinosad)
Used in organics
|
334 mL/ha
(135 mL/acre)
|
7 |
|
Scorpio Ant and Insect Bait(spinosad) Group 5 |
25 to 50 kg/ha (10.1 to 20.2 kg/acre) |
7 |
|
Minecto Pro(abamectin/ cyantraniliprole) Group 6 & 28 |
370 mL/ha (150 mL/acre) Apply in 200 L/ha (80 L/acre) of water |
14 |
|
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 |
|
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 |
|
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 |
|
*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.
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 |
|
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 |
|
Agri-Mek SC(abamectin)
Group 6
|
225 mL/ha
(90 mL/acre) Apply in 185 L/ha (75 L/acre of water.
|
14 |
|
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 |
|
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 |
|
*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:
- Winter fallow suspect fields: work up in the preceding late summer or fall and keep weeds down until potatoes are seeded.
- 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.
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 |
|
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 |
|
Scorpio Ant and Insect Bait(spinosad) Group 5 |
25 to 50 kg/ha (10.1 to 20.2 kg/acre) |
N/A |
|
Cimegra(broflanilide) Group 30 |
*Note: for 90 cm row spacing. In-furrow: 250 mL/ha (101 mL/ac) Or: 2.3 mL per 100 m of row Apply in 50 L/ha (20 L/ac) of water
|
N/A |
|
*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:
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.
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 |
|
7 (carboxamide) (SDHI) |
Vertisan(penthiopyrad) |
15.5 to 31 mL per 100 m row | N/A |
|
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 |
|
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 |
|
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 |
|
|
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 |
In-Furrow Application:
Post-plant applications:
|
44 |
Double Nickel 55(Bacillus amyloliqufaciens strain D747) |
Soil application:
0.2 to 1 kg/ha
(80 to 400 g/acre) |
N/A |
|
44 |
Double Nickel LC(Bacillus amyloliqufaciens strain D747) |
Soil application:
1 to 5 L/ha
(0.4 to 2 L/acre)
|
N/A |
|
*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
- Disinfect the cutting knife after cutting partially rotted tubers.
- Disinfect custom or shared seed cutters or planters between farms (see Bacterial Ring Rot, this section).
- 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.
- Use of small, whole seed is an effective preventive measure when practical.
- 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
- If possible, turn under crop residue promptly after harvest.
- Avoid replanting fields which had a severe early blight problem the previous year.
- Ensure adequate nitrogen fertility.
- Keep weeds under control.
- A spray program for late blight will also help to control early blight (see table below).
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 |
|
M5 (chloronitrile) |
Bravo ZN(chlorothalonil) |
1.6 to 2.4 L/ha (0.6 to 1.0 L/acre |
2 |
|
M5 (chloronitrile) |
Echo 90DF(chlorothalonil) Note: no longer produced. Registration expires May 2021. |
0.9 to 1.3 kg/ha (400 to 500 g/acre) |
1 |
|
M5 (chloronitrile) |
Echo 720(chlorothalonil) |
1.1 L/ha (400 mL/acre) |
1 |
|
M (phthalimide) |
Maestro 80 DF(captan) Note: no longer produced. Registration expires May 2021. |
2.5 to 3.75 kg/ha (1.0 to 1.5 L/acre) |
7 |
|
M (dithiocarbamate) |
Dithane DG
|
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Dithane F-45(mancozeb) |
1.8 to 3.8 L/ha (0.7 to 1.5 L/acre) |
1 |
|
M (dithiocarbamate) |
Penncozeb 75DF(mancozeb) |
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Penncozeb 75DF Raincoat(mancozeb) |
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Polyram DF(metiram) Note: no longer produced. Registration expires June 2021. |
1.1 to 1.75 kg/ha (450 to 700 g /acre) |
1 |
|
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 |
|
M (inorganic) |
Parasol F(copper hydroxide) |
0.8 to 1.8 L/ha (320 to 720 mL/acre) |
1 |
|
M (inorganic) |
Kocide 2000(copper hydroxide)
Used in organics. |
0.8 to 1.6 kg/ha (300 to 350 g/acre) |
1 |
|
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 |
|
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 |
|
M (inorganic) |
Copper 53W(tri-basic copper sulphate) |
3.8 kg/ha (1.5 kg/acre) |
1 |
|
M1 (inorganic) |
Cueva(copper octanoate) Used in organics |
Use a 0.5% to 2% solution at 470 to 940 L/ha (190 to 380 L/acre) | 1 |
|
M4 dithiocarbamate) |
Ridomil Gold/ Bravo Twin Pak(metalaxyl-M/ chlorothalonil) Note: no longer produced. Registration expires May 2021. |
See label for specific rates | N/A |
|
Ridomil MZ 68 WP(metalaxyl/ mancozeb) Note: no longer produced. Registration expires April 2023 |
||||
3 (triazole) |
Quash(metconazole) |
175 to 280 g/ha |
1 |
|
3 (isopropanol-triazole) |
Cevya(mefentrifluconazole) |
0.19 to 0.25 L/ha (77 to 100 mL/acre) | 7 |
|
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 |
|
7 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 |
|
7 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 |
|
7 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 |
|
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 |
|
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 |
|
7 & 3 (pyrazole carbmoxamide (SDHI) /triazole) |
Miravis Duo(pydiflumetofen & difenoconazole) |
1.0 L/ha (405 mL/ac) Apply in 150 L/ha (60 L/ac) of water |
14 |
|
7 & 3 (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 |
|
9 (anilnopyrimidine) M |
Scala SC(pyrimethanil) Plus: (chlorothalonil) |
750 mL/ha Plus: |
7 |
|
11/ M2 (strobilurin/ dithiocarbamate) |
Cabrio Plus(pyraclostrobin/ metiram) Note: no longer produced. Registration expires June 2021. |
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 |
|
11/M (strobilurin) |
Reason 500SC(fenamidone) Plus: (mancozeb) |
200 mL/ha 1.25 kg/ha (500 g/acre) |
14 |
|
11 (strobilurin) |
Acapela(picoxystrobin) |
0.6 to 1 L/ha Apply in 110 L/ha (45 L/ac) of water |
3 |
|
11 (strobilurin) |
Quadris F(axosystrobin) |
500 to 800 mL/ha (200 to 300 mL/acre) |
1 |
|
11 (strobilurin) |
Headline EC(pyraclostrobin) |
450 to 670 mL/ha (200 to 270 mL/acre) |
3 |
|
11 U 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 |
|
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 |
|
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 |
|
19
(polyoxin)
|
Diplomat 5SC(polyoxin D zinc salt)
|
537 to 926 mL/ha
(217 to 375 mL/acre)
|
0 |
|
22
M
22
M (dithiocarbamate) |
Zoxium 80W(zoxamide) Plus: (mancozeb) Or (zoxamide) Plus: |
175 g/ha
Plus:
Or Plus: (800 g/acre) |
3 |
|
22 & M3 |
Gavel DF(mancozeb / zoxamide) |
1.7 kg/ha (700 g/acre) |
3 |
|
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 |
|
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 |
|
*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
- Wait until soil warms up before planting.
- 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.
- 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.
- 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.
- 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).
- 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
- Avoid replanting fields which had severe late blight the previous year.
- 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.
- 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.
- 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.
- 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.
- Ensure potatoes are well hilled.
- 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.
- 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.
- 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.
- 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.
Group | Product | Rate | PHI* | Comments |
---|---|---|---|---|
(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 |
|
M5 (chloronitrile) |
Bravo ZN(chlorothalonil) |
1.2 to 2.4 L/ha (0.5 to 1.0 L/acre) |
2 |
|
M5 (chloronitrile) |
Echo 90DF(chlorothalonil) Note: no longer produced. Registration expires May 2021. |
0.7 to 1.3 kg/ha |
1 |
|
Echo 90WSP(chlorothalonil) |
0.7 to 1.3 kg/ha 1kg WSP per 0.77 to 1.43 ha (1.9 to 3.5 ac) |
|||
M5 (chloronitrile) |
Echo 720(chlorothalonil) |
0.8 to 1.7 L/ha (300 to 700 mL/acre) |
1 |
|
M (phthalimide) |
Maestro 80 DF(captan) Note: no longer produced. Registration expires May 2021. |
2.5 to 3.75 kg/ha (1.0 to 1.5 L/acre) |
7 |
|
M (dithiocarbamate) |
Dithane DG
|
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Dithane F-45(mancozeb) |
1.8 to 3.8 L/ha (0.7 to 1.5 L/acre) |
1 |
|
M (dithiocarbamate) |
Penncozeb 75DF(mancozeb) |
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Penncozeb 75DF Raincoat(mancozeb) |
1.1 to 2.25 kg/ha (450 to 900 g/acre) |
1 |
|
M (dithiocarbamate) |
Polyram DF(metiram) Note: no longer produced. Registration expires June 2021. |
1.1 to 1.75 kg/ha (450 to 700 g /acre) |
1 |
|
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 |
|
M (inorganic) |
Parasol F(copper hydroxide) |
0.8 to 1.8 L/ha (320 to 720 mL/acre) |
1 |
|
M (inorganic) |
Kocide 2000(copper hydroxide)
Used in organics.
|
0.8 to 1.6 kg/ha (300 to 350 g/acre) |
1 |
|
M (inorganic) |
Copper Spray(Fixed Copper) |
4.0 kg/ha
(1.6 kg/acre)
|
1 |
|
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 |
|
M (inorganic) |
Copper 53W(tri-basic copper sulphate) |
3.8 kg/ha (1.5 kg/acre) |
1 |
|
M (inorganic) |
Cueva(copper octanoate) Group M1 Used in organics |
Use a 0.5% to 2% solution at 470 to 940 L/ha (190 to 380 L/acre) | 1 |
|
4 M dithiocarbamate) |
Ridomil Gold/ Bravo Twin Pak(metalaxyl-M/ chlorothalonil) Note: no longer produced. Registration expires May 2021 |
See label for specific rates | N/A |
|
Ridomil MZ 68 WP(metalaxyl/ mancozeb) Note: no longer produced. Registration expires April 2023 |
||||
11 M2 (strobilurin/ dithiocarbamate) |
Cabrio Plus(pyraclostrobin/ metiram) Note: no longer produced. Registration expires June 2021. |
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 |
|
11 (strobilurin) |
Acapela(picoxystrobin) |
0.44 to 1 L/ha Apply in 110 L/ha (45 L/ac) of water |
3 |
|
11 |
Headline EC(pyraclostrobin) |
450 to 670 mL/ha (200 to 270 mL/acre) |
3 |
|
11 (strobilurin) |
Reason 500SC(fenamidone) Plus: Rainshield NT (mancozeb) |
200 mL/ha Plus: |
14 |
|
11 U 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 |
|
22
M
22
M |
Zoxium 80W(zoxamide) Plus: Rainshield NT (mancozeb) Or (zoxamide) Plus: 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 |
|
22 & M3 benzamide) |
Gavel DF(mancozeb / zoxamide) |
2.25 kg/ha (900 g/acre) |
3 |
|
21 |
Ranman 400SC(cyazofamid)
|
100 to 200 mL/ha (40 to 80 mL/acre) |
7 |
|
27
M |
Curzate 60 DF(cymoxanil) Plus: (mancozeb) |
225 g/ha
Plus: |
8 |
|
29 (pyradinamine) |
Allegro 500F(fluazinam) |
400 mL/ha (160 mL/acre) |
14 |
|
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 |
|
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 |
|
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
|
|
33 (phosphonate) |
Phostrol(mono- and dibasic sodium, potassium, and ammonium phosphites) |
Post-harvest:
0.42 L water to 1 tonne tubers
|
N/A |
|
33 (phosphonate) |
Confine(mono- and di-potassium salts of phosphorous acid) |
Post-harvest: dilute at a 1:4.3 ratio with water | N/A |
|
33 (phosphonate) |
Rampart(mono- and dipotassium salts of phosphorous acid) |
Post-harvest: dilute 190 mL of product in 1 L of water | N/A |
|
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 |
|
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 |
|
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 |
|
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 |
|
49 |
Orondis(oxathiapiprolin) |
120 to 350 mL/ha
(49 to 140 mL/acre
Apply in 110 L/ha (45 L/acre) of water.
|
5 |
|
*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
- Use only certified seed.
- Rogue seed fields early and often, including all volunteers (carry plant and seed-piece clear of field and bury if practical).
- Do not plant susceptible varieties such as Russet Burbank in fields which have volunteers from the previous year or adjacent to fields with volunteers.
- 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.
- If you are growing your own seed, set seed plot away from edge of field.
- 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.
- 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.
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 |
In-Furrow Application:
Post-plant applications:
|
4 M (phenylamide/ chloronitrile) |
Ridomil Gold/Bravo Twin Pak(metalaxyl-M / chlorothalonil) Note: no longer produced. Registration expires May 2021 |
1 jug per 4 ha (1 jug per 10 acres) |
N/A |
|
4 M (phenylamide/ chloronitrile) |
Ridomil Gold MZ 68WP(metalaxyl-M/ mancozeb) Note: no longer produced. Registration expires April 2023 |
2.5 kg/ha (1.0 kg/acre) |
N/A |
|
4 (phenylamide) |
Ridomil Gold 480 SL(metalaxyl-M) |
4 to 6 mL of product per 100 m of row | 90 |
|
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 |
|
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 |
|
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 |
|
33 (phosphonate) |
Phostrol(mono- and dibasic sodium, potassium, and ammonium phosphites) |
Post-harvest: 0.42 L water to 1 tonne tubers |
N/A |
|
(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 |
|
33 (phosphonate) |
Rampart(mono- and dipotassium salts of phosphorous acid) |
Post-harvest: dilute 190 mL of product in 1 L of water | N/A |
|
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 |
|
49 |
Orondis(oxathiapiprolin) |
In-furrow:
6.4 ml/100 m row length
Apply in 40 L/ha (16 L/ac) of water
|
N/A |
|
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 |
|
*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
- Use seed potatoes certified free of root-knot nematode.
- Destroy all culls and volunteers from previous potato crops.
- Where the northern root-knot nematode is present, rotation with small grains, grasses and corn is recommended, while alfalfa should be avoided.
- Fumigate in late summer with Vapam according to label directions.
Group | Product | Rate | PHI* | Comments |
---|---|---|---|---|
7 |
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 |
|
*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
- Avoid planting infected seed pieces.
- Avoid planting potatoes in fields where volunteers are likely to grow.
- Harvest tubers as soon as they are mature.
- 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.
- 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).
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 |
|
11 (strobilurin) |
Quadris F(axosystrobin) |
4 to 6 mL of product per 100m of row | 90 |
|
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 |
|
*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
- Practice crop rotation, avoiding tomatoes, peppers, eggplants and melons.
- High rates of nitrogen fertilizer delay the appearance of symptoms.
- 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.
- Windrowing and burning infected tops promptly after harvest will reduce inoculum carryover but may encourage scab in succeeding potato crops.
- Senator seed piece treatment is registered for verticillum wilt. See Potatoes Seed Piece Treatments section of this page.
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 |
|
*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
Group | Product | Rate | Comments |
---|---|---|---|
M |
Tuberseal(mancozeb)
|
500 g per 100 kg of seed (4.5 kg per ton of seed) |
|
M |
Potato ST16(mancozeb)
|
500 g per 100 kg of seed (4.5 kg per ton of seed) |
|
1 |
Senator 50 SC(thiophanate-methyl)
|
1.4 L of product per 6.5 L of water 6.5 L of solution per 1400 kg of seed |
|
Group | Product | Rate | Comments |
---|---|---|---|
1 |
Senator 50 SC(thiophanate-methyl)
|
1.4 L of product per 6.5 L of water 6.5 L of solution per 1400 kg of seed |
|
1 |
Senator PSPT(thiophanate-methyl)
|
500 g per 100 kg of seed (4.5 kg per ton of seed) |
|
M3 & 12 |
Maxim MZ PSP(fludioxonil & mancozeb)
|
500 g per 100 kg of seed (4.5 kg per ton of seed) |
|
Maxim PSP(fludioxonil)
|
|||
12 & 3 |
Maxim D(fludioxonil & difenoconazole)
|
130 mL per 100 kg of seed (1.2 L per ton of seed) |
|
Heads Up(Saponins of Chenopodium quinoa)
|
1 g per L of water 1 L of solution per 100 to 264 kg of seed |
|
|
3 & 7 |
Emesto Silver(penflufen & prothioconzole)
|
20 mL/100 kg of seed |
|
3, 7 & 40 |
Vibrance Ultra Potato(sedaxane/ difenoconazole/ mandipropamid) |
32 mL/ 100 kg of seed |
|
3 & 12 fungicides & 4 insecticide |
Cruiser Maxx Potato Extreme(fludioxonil/ difenoconazole/ thiamethoxam)
|
20 mL per 100 kg of seed |
|
Group | Product | Rate | Comments |
---|---|---|---|
3, 7 & 40 |
Vibrance Ultra Potato(sedaxane/ difenoconazole/ mandipropamid) |
32 mL/ 100 kg of seed |
|
40 |
Revus(mandipropamid) |
13 - 26 mL/ 100 kg of seed |
|
Group | Product | Rate | Comments |
---|---|---|---|
4 |
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 |
|
4 |
Actara 240 SC(thiamethoxam)
|
See label for rate per 100 kg of seed. |
|
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) |
|
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
|
|
28 |
Fortenza(cyantraniliprole)
|
10 to 22.5 mL per 100 kg of seed pieces |
|
Group | Product | Rate | Comments |
---|---|---|---|
4 |
Titan ST(clothianidin)
|
20.8 mL per 100 kg of seed (188.7 mL per ton of seed) |
|