We are increasingly encountering a variety of difficultly to control plant diseases in vegetable fields. One management tool that could be used more widely to help in the control of plant diseases is rotation. Many diseases build up in the soil when the same crop is grown in the same field year after year. Rotation can help break this cycle and stop the buildup of disease organisms in the field. To be effective, rotations must be carefully planned. The present crop and all related plants or alternate hosts for the disease must be kept out of the field. Only those crops not susceptible to the disease should be grown there. Different plant diseases will persist in the soil for different lengths of time, so the length of the rotation will vary with the disease being managed. The following table lists many of the vegetable crop diseases that can be affected by rotation and the length of rotation that is required.
| Rotation Periods Suggested to Help Control Vegetable Diseases | ||
| Vegetable | Disease | Period Without a Susceptible Crop |
| Asparagus | Fusarium wilt, root rot | Indefinitely; do not replant without fumigation |
| Beans | Root rots | Several years |
| Pod white mold | Several years, avoid potato, tomatoes, lettuce, cabbage | |
| Anthracnose | Two years | |
| Bacterial blight | Two years | |
| Beets | Cercospira leaf spot | Three years |
| Cabbage-related plants | Clubfoot | Seven years; avoid turnip and radish |
| Fusarium yellows | Many years | |
| Blackleg | Three to four years; avoid turnip | |
| Black rot | Two to three years; avoid turnip | |
| Carrots | Leaf blights | Few years |
| Celery | Leaf blights | Few years |
| Corn, sweet | Smut | Few years |
| Yellow leaf blight | Three years | |
| Northern corn leaf blight | Few years | |
| Cucumber | Scab and leaf spot | Two years |
| Eggplant | Verticillium wilt | Four years; avoid tomato, potato, pepper, strawberry, brambles |
| Fruit rots | Three years | |
| Lettuce | Bottom rot and drop | Three years |
| Muskmelon | Leaf spots | Two plus years; avoid watermelon, pumpkin and squash |
| Scab | Two plus years; avoid cucumber, pumpkin and squash | |
| Fusarium wilt | Several years. Disease is different from watermelon fusarium wilt | |
| Vegetable | Disease | Period Without a Susceptible Crop |
| Onion | Leaf blights | One to two years |
| Parsley | Damping-off | Three years |
| Parsnip | Leaf spot and root canker | One to two years |
| Peas | Root rots | Three to four years |
| Fusarium wilt | Four to five years | |
| Peppers | Bacterial spot | One to two years |
| Phytophthora blight | Two years; also avoid tomato and eggplant | |
| Potato | Verticillium wilt | Three to four years without tomatoes |
| Sclerotinia stalk rot | Four years | |
| Rhizoctonia canker | Two to three years, preferably with two grasses or one cereal | |
| Pythium leak and pink rot | Four years | |
| Common scab | Three to four years; no root crops | |
| Pumpkin & Squash | Black rot | Two plus years; avoid muskmelon and watermelon |
| Radish | Clubfoot | Seven years; avoid turnip and cabbage-related plants |
| Turnip | Clubfoot | Seven years; avoid radish and cabbage-related plants |
| Spinach | Downy mildew | Two years |
| Sweet potato | Black rot and scurf | Three years |
| Pox | Few years | |
| Tomato | Bacterial canker | Three years |
| Bacterial speck | One year | |
| Bacterial spot | Two years; avoid pepper | |
| Early blight | Two years; avoid potato | |
| Anthracnose | Two plus years | |
| Fusarium wilt | Three years | |
| Verticillium wilt | Several years; as long as possible; avoid potato | |
| Watermelon | Black rot | Two plus years; avoid muskmelon, pumpkin and squash |
| Fusarium wilt | Several years. Disease is different from muskmelon fusarium wilt | |
Originally from: Vegetable Newsletter, Vol. 19, No.4, Pennsylvania State University, A. MacNab, April 1990.
Revised by: Richard A. Ashley, Extension Specialist – Vegetables, April 1994.
Reviewed by: T. Jude Boucher, UConn IPM, 2012
The information in this document is for educational purposes only. The recommendations contained are based on the best available knowledge at the time of publication. Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. The Cooperative Extension System does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available. The University of Connecticut, Cooperative Extension System, College of Agriculture and Natural Resources is an equal opportunity program provider and employer.