Sitka Spruce Tree Breeding Program

Sitka spruce (Picea sitchensis (Bong.) Carr.) is an integral component of the coastal rainforest of western North America. A pest resistance screening and breeding program against the white pine weevil (Pissodes strobi) has been ongoing in British Columbia since the early 1980s.

In recent years, the main effort has been monitoring weevil attacks in the first-generation (F-1) trials. The last site where F-1 trials were established, located at Pinch Creek, was augmented with weevils in 2015. The evaluation that followed found that fewer than three percent of trees became infested with weevils.

In addition to ongoing monitoring for weevil attacks, the Sitka spruce program plans to provide an analysis of all genetic trials to date, in order to provide both resistance and growth estimates for orchard upgrading. Depending on the results, stable and effective resistance with volume gain may be delivered through current upgraded orchards. The selections from these trials may undergo another cycle of weevil enhancement for further development of resistance and volume gain.