When it comes to snow (Figure 1.), most producers growing winter crops, i.e. wheat, canola and/or peas, welcome the protection that a layer of snow cover can provide especially if below freezing temperatures are in the forecast. However, snow that remains on wheat greater than 100 days can lead to the development of “Snow Mold.” Growers who have chosen winter wheat varieties that are susceptible to snow mold, such as ORCF-102 or Puma, may find their fields/plants severely impacted come spring. For a complete list of “Snow Mold Ratings” for various varieties, visit the WSU Wheat & Small Grains Variety Selection Tool.
As little as one to two inches of snow can provide a favorable micro-climate and protect against potential sub-zero temperatures that can be detrimental to the crown zone of plants. It can also protect plants from cold, dry winds which can make plants like wheat susceptible to dehydration. While snow cover may be beneficial on one hand, it may also be detrimental on the other. Those same favorable micro-climate conditions can also keep pestiferous insects like Grasshoppers, Cabbage Seedpod Weevil and others from being killed by any ultra-cold temperatures.
Therefore, it is always recommended to scout for insect pest populations during the spring/early summer months to determine if their numbers have reached the “Action or Treatment Threshold”. This threshold is the number of pests that, if not controlled, may continue to multiply and reach the “Economic Injury Level”. This level is defined as a pest population density where the cost of control measures are equal to or greater than the amount of damage caused to the crop. For more information on insect pests, visit our Insect Resources page.
For questions or comments, contact Dale Whaley by email at dwhaley@wsu.edu or by phone at 509-745-8531.