All the isolates of late blight -Phytophthora infestans tested were US-23 for 2017. No new late blight incidence has been reported in the last week, which has generally been dry, warm and windy. The 7-day DSV accumulation for late blight risk has been essentially minimal. Harvest has begun in many areas.
The warm conditions has slowed the harvest of some processing fields, to prevent bringing warm tubers into storage. The seasonal accumulated precipitation has been 50-70% of normal in the potato growing areas (Fig1). The soils are generally on the dry side (Fig 2), but irrigated fields have sufficient moisture for a good harvest.
Early dying due to apparent Verticillium wilt has been seen, along with blackdot infected stems in some fields.
This will be the last potato disease report for 2017.
I take this opportunity to thank all the agronomists (Ron Lintott & Trevor Thornton (Crop Care), Steve Saunderson (ChoiceAgri), Colby Robertson & Cole Ritchie (McCain Foods), Landon Thomson & Leon Jarvis (Simplot), Kurt Ginter (KR CropCheck), Darren White (DeltaAg) and MB Agriculture staff (Tracey Cummer, Sunil Kawthekar, Brett Skeoch, Mildred Valentino, David Osterman, Manika Pradhan: who provided crop & pest information, disease samples or supported the aphid, ECB and potato psyllid monitoring programs. Finally a big thanks to WIN (Weather Innovation Consulting LP) for maintaining the www.mbpotatoes.ca and support for late blight forecasting.