Infection takes place primarily in the fall, but symptoms do not develop until the following spring. Severely diseased plants will be slow to grow during early plant development and may be stunted and thin throughout the season. The variety Saluda develops an extreme yellow leaf reaction which is usually noted in the crop throughout the season.
Symptoms are most severe in springs following a consistently cold winter.
Symptoms are less intense following winters and early springs where numerous mild days were experienced at regular intervals. In most years, infections become symptomless as temperatures warm in the spring. The only way to control WSSM is to plant resistant varieties and delay planting until mid October or later. Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability, or national origin.