Do not plant potatoes in areas of fields where plants cannot be sprayed with fungicide. Consider not planting the area under the first few nozzles of a center pivot system where plants remain wet for extended periods. During Planting Do not mix seed lots to avoid possible contamination of healthy seed by infected seed. Early Season Cultivate fields to increase water infiltration and control weeds. Form high, wide hills to reduce exposing tubers to late blight spores that may be washed from infected plants.
Scout fields regularly concentrating in areas that remain wet for extended time periods.
Look for early indications of late blight on volunteer potatoes and monitor cull disposal sites. Midseason Apply heavier, less frequent water applications rather than light, frequent ones. For night irrigation sets, consider beginning after midnight when dew would normally wet the leaves anyway. Continue scouting, especially low lying areas, pivot corners, field borders, and weedy patches. Although late blight readily spreads with moist air, to reduce any risks, people entering fields may want to wear high boots that can be disinfected between fields, or wear disposable boots and pants that can be changed between fields, and reused after washing and drying.