Recent research presented at the N.B. Potato Conference and Tradeshow, Feb. 6th 2020, has highlighted the low levels of Potato virus Y (PVY) in the 2019 seed harvest in New Brunswick, Potato Country magazine reports.
The research was headed by Drs. Mathuresh Singh and Tyler MacKenzie of Potatoes New Brunswick’s Agricultural Certification Services (ACS) lab in Fredericton N.B. ACS is the primary lab for testing and certifying seed lots for the N.B. potato industry, and maintains an important ongoing research program testing best management practices for reducing PVY spread in the province.
Dr. MacKenzie’s recent presentation showed how PVY levels in the N.B. industry have dropped dramatically since 2009, and explained that the lower levels of PVY in the industry follow the instituting of strict regulatory limits on PVY in seed lots last decade, and careful in-field management by growers of this aphid-spread virus.
Average PVY level in all tested potato seed lots harvested in 2009 was 11.8%, which over a decade dropped to only 0.63% in the 2019 harvest. This is near to the lowest level ever measured in the N.B. potato industry, which was 0.43% in the 2016 harvest.
More important than the average PVY in the seed potato harvest, though, is the number of seed lots rejected due to PVY level exceeding the provincially-mandated virus cap. Currently, this cap for PVY is 4%, and harvested lots testing higher than this cannot be sold as potato seed in N.B. From the 2019 harvest, 98.1% of seed lots were below this threshold for rejection, near the record performance of the 2016 crop at 98.4% of seed lots accepted under the same strict virus cap.
Photo: Image of PVY-infected potato plant (var. Goldrush) center, with uninfected plant at right (photo courtesy PotatoesNB and ACS Inc.)