Short rotations increase the risk of yield loss caused by brown stem rot. The host range of P. gregata is limited to soybean, adzuki bean and mung bean. Therefore, two or more years of nonhost crop is very beneficial to suppress BSR. Corn, small grains and forage legumes are all good rotation crop choices. 

Pea and snap bean provide some benefit for reducing BSR potential, but are hosts to the soybean cyst nematode and white mold pathogen, and therefore increase the risk of these diseases developing.

Many farmers in the North Central states have converted to an annual rotation of corn and soybean. An annual corn-soybean rotation is advantageous to corn, as it reduces the need for insecticides to control corn rootworms and the amount of N fertilizer required for profitable corn production. Unfortunately, soybean does not benefit as greatly from this annual crop sequence, especially for varieties that are susceptible to BSR. Thus, other management practices are needed to improve soybean health in the corn-soybean rotation.

Rotate resistant varieties
We propose to expand the concept of crop rotation to include the rotation of soybean varieties in the soybean year of the rotation sequence. The direct benefit of resistant varieties has been thoroughly documented. However, our data indicates that brown stem rot resistant varieties provide a "rotation effect" which is not achieved with susceptible varieties.

Yield of the BSR-susceptible variety (41.6 bu/a) was lowest in the rotation that alternated corn with susceptible soybean. The presence of a BSR-resistant variety two years prior resulted in a higher yield of the susceptible soybean variety (47.7 bu/a) in the alternating sequence of corn and soybean (Table 1).