Hot and dry weather means more disease in soybeans

Hot, dry weather goes hand-in-hand with root and stem diseases in soybeans, adding to farmers’ worries in one of the driest seasons in years.

OMAFRA plant pathologist Albert Tenuta says farmers should be scouting for stem canker, fusarium wilt and charcoal rot, which can survive in the soil residue from year-to-year. He cautions that many of the diseases can occur in the same field, citing a field in Essex County that had all three. Fusarium wilt and charcoal rot mimick drought stress, so identifying them is a challenge.

Soybean cyst nematode can further add stress, allowing easier access for many soil-borne root pathogens.

While fungicide seed treatments can help with early infections, it won’t stop late-season infections. Foliar fungicides have only been effective against stem canker and the results are inconsistent.

Tenuta says identifying infected fields before next year can help determine the best management options going forward.