White mold is a common fungal pathogen found in soybeans that is caused by the sclerotinia sclerotiorum. The spores infect plants mainly through colonized blossoms, can prevent successful pod development and greatly depress yield. Importantly, the pathogen can be scattered back into the soil during harvest and survive over winter (and in certain cases for years).


Early signs of white mold can be seen in pod development and can most commonly be observed near colonized flowers. Leaves may wilt, curl and die. Diseased stem areas may bleach and shred easily. The life cycle of the fungus makes it challenging to control with standard chemical pesticides.


There are several cultural practices to manage white mold in the field. The first line of defense is genetics. Growers can select a variety of soybeans that have resistance against white mold. A resistant variety will have a much higher chance of surviving if white mold and favorable conditions (for the mold) exist. Row spacing can also play a large role. Wider 30-inch rows can help in delaying canopy which reduces favorable conditions for the disease. Another cultural control to help prevent white mold would be lowering the planting population of the soybeans to allow for greater cellular respiration rates and less humidity in the canopy.


In addition to these cultural practices, there have been considerable advancements in biological seed treatments. There are now biological controls in seed treatment that are effectively suppressing white mold. These seed treatments work to provide season long protection against pathogens by harnessing the plant’s natural power. Certain biological seed treatments can help prime the plant’s innate defense system so it is better prepared to fight the disease when it surfaces.


Having an integrated pest management plan and taking a preventative approach from the start through seed treatment can increase the effectiveness compared to relying solely on the more reactive approaches. Give us a call today to learn how applying biological seed treatments with your My Yield® seed treater can help your crop better defend against white mold and other pathogens from the start.