North Dakota State University (NDSU) plant pathologist Dr. Gary Secor announced July 27 that late blight was confirmed in a potato sample from Pembina County in northeast North Dakota. Since then it has been determined the outbreak is more widespread with finds in Walsh and Nelson Counties as well.
Conditions have been favourable for late blight spread and infection, and growers in these areas should apply a late blight specialty fungicide such as Orondis or Revus Top immediately. All growers in northeast North Dakota and northwest Minnesota should scout potato fields for late blight and be ready to apply late blight fungicides.
Late blight samples in these areas can be sent to NDSU so they can identify the genotype in order to help with management.
Potato Psyllid Detected
Potato psyllid, Bactericera cockerelli, has been detected in a commercial potato field in Stutsman County in central North Dakota. Several yellow sticky cards were submitted to the NDSU Plant Diagnostic Lab and Extension Entomology by a crop consultant. One of the cards contained three potato psyllids. Species identification was confirmed using DNA analysis.
The potato psyllids also were tested for Liberibacter, the causal agent of zebra chip disease in potatoes. All three potato psyllids tested negative for Liberibacter.
Potato growers should be monitoring their fields for potato psyllids.
More information on potato psyllids, including biology and control information: Management of Potato Psyllids – 2016.
Source: Northern Plains Potato Growers Association