Sweetpotato and white potato growers can establish all or part of their acreage with certified seed. Seed of some crops, such as lettuce, can be tested for disease incidence. Seed, both true seed and that of vegetatively propagated plants can also be treated. Treatments include hot water, bleach solutions and fungicides, depending on the disease. Although crop rotation, especially between very different crops, is generally considered to reduce disease, it is not clear to what extent disease prevention contributes to the benefit of rotation.
Rotation is most effective against diseases that attack only one crop.
However, controlling the many diseases that infect several crops in the same plant family requires rotation to an entirely different family. Unfortunately some pathogens, such as those causing wilts and root rots, attack many families and rotation is unlikely to reduce disease. Diseases common in the south and crop species susceptible to them are listed alphabetically on the previous page as a convenient guide for planning crop rotations. Information on the impact of cover crops on disease damage to the subsequent cash crop is limited, but cover crops have been used in some crops to suppress disease. Soil populations of Pythium were greater after all legume cover crops compared to the winter fallow treatment.