Avoid planting potatoes in the same field year after year. Proper crop rotations enhance soil fertility, help maintain soil structure, reduce certain pest problems, increase soil organic matter, and conserve soil moisture. Herbicides not available for use in potatoes can be used in certain rotation crops to control problem weeds. However, be sure to check these herbicide labels for any plant-back restrictions concerning future potato crops. Whenever possible, use rotations that reduce problem pests and avoid rotations that may increase them.
If your field is infested with pathogens or nematodes listed in the table below, consider choosing a listed nonhost crop. Although longer nonhost crop rotations are ideal, they often are not economically feasible. A rotation of lesser duration is still beneficial but to a lesser degree. In general, avoid solanaceous crops as rotation choices. Control volunteer potatoes and weeds in the rotation crop.
For winter annual weed control, choose a small grain crop and control these weeds with a suitable herbicide. Manage summer annual weeds by growing a small grain (Klamath Basin) or using corn as a rotation crop so that selective herbicides and cultivations can be used.
|Pest problem||Rotation cycle (years)||Rotation crop options and other comments|
|Bacterial ring rot||1 +||Nonpotato crop; control volunteer potatoes|
|Black dot||3 +||Nonsolanaceous crop; control solanaceous weeds and volunteer potatoes|
|Common scab||1 +||Cereals; green manure cover crops such as rye, millet, and oats|
|Late blight||1 +||Nonsolanaceous crop; control solanaceous weeds and volunteer potatoes|
|Powdery scab||3 +||Nonsolanaceous crop; control solanaceous weeds and volunteer potatoes|
|Silver scurf||1 +||Nonsolanaceous crop; control solanaceous weeds and volunteer potatoes|
|Stem and stolon canker||2–3||Non-potato crop but not sugarbeet; control potato volunteers|
|Stem rot||3||Small grains|
|Verticillium wilt||2–3||Cereals, grasses, legumes; control weeds|
|White mold||1 +||Cereals, grasses; control weeds|
|Wireworms||3 +||Alfalfa; control weeds|
|Columbia root-knot nematode||2 +||Sordan79 sudangrass, alfalfa (for race 1)|
|Northern root-knot nematode||2 +||Small grains|
|Southern root-knot nematode||2 +||Nematode-resistant tomato cultivars|
|Weeds||1 +||Control problem weeds|