ABSTRACT
According to Sumner and Boosalis, conservation tillage and minimum tillage practices may increase, decrease, or have no effect on plant diseases. Tillage practices may also indirectly influence plant diseases by affecting the rate and/or uptake of nutrients, the application or types of fertilizers and pesticides, dates of planting, germination rate of seeds and emergence of seedlings, and root distribution. Certain pathogens which depend on crop residues for nutrients and overwintering sites may survive in any conservation tillage system while others may require specialized conditions found only in selected tillage systems combined with certain cropping sequences. Plant residues from conservation tillage operations provide an excellent source of overwintering inoculum for many field crops. Research has shown that residues provide a means of survival for common plant diseases including several important leaf blights of corn. Control of plant diseases in conservation tillage systems requires an integrated approach emphasizing alternatives to clean plowing.
