The Relationship of Dry Bean and Sugar Beet Pathogens with Common Weeds in Nebraska Production Fields

Rotating nonhost crops with dry edible beans and sugar beets has been shown to reduce the effects of several pathogens and their diseases on subsequent crops. Examples of this phenomenon include sugar beet cyst nematode, Aphanomyces root rot and Fusarium yellows in sugar beets with Fusarium yellows and root rot in dry beans. These particular diseases are specific to their respective crops. Therefore, by breaking the cropping cycle with nonhosts, the build-up of the pathogens causing disease should theoretically be reduced in these cases. Other pathogens such as Rhizoctonia and Pythium are less specific and more versatile in the plants they are capable of attacking; therefore, rotation would likely have little effect on reducing the severity of these diseases. However, in either case, the presence of infected weeds in fields could easily nullify the desired benefits of rotation for disease reduction by harboring or increasing certain pathogens that could subsequently attack new sugar beet and/or dry bean crops.