Although historically documented to occur in even years in the Midwest, the white mold pressure of 2009 proved this theory wrong. White mold caused by sclerotinia sclerotiorum devastated many farmers' fields in 2009 — with some reporting losses of up 40 bushels per acre in soybeans. The pressure was wide spread with reports of white mold outbreaks from most of the soybean and edible bean production states. The story doesn't stop in 2009, with record levels of Sclerotinia being returned to the soil in advance of the 2010 planting season.
Since sclerotia (small black bodies seen at harvest) are known to overwinter and last in the soil for seven to 10 years, it is very important to manage white mold similar to managing weed populations — with a proactive and ongoing program. Regular management of sclerotinia populations will net big paybacks in terms of yield for growers.
According to Scott Peterson, product manager with SipcamAdvan, "One way to manage this harmful disease is by attacking it at the source with Contans WG. Contans is soil applied early in the spring and attacks the sclerotia before they can release spores." University research has shown that an IPM approach for managing white mold is crucial in combating this yield robbing organism.
The benefit of treating early in the spring is that Contans reduces the source of disease pressure (sclerotia) early in the season; before the disease infects the crop. Even during a non-white mold year, Contans works in the soil to reduce the fungus population, similar to how annual applications of herbicides reduce the weed seed bed year after year.
Mild damp weather throughout the Midwest is again creating optimal conditions for the widespread development of white mold in soybeans, edible beans, canola and sunflowers. Early management of white mold is key to protecting yields and applying Contans to the soil pre planting will effectively reduce the source of inoculum and the incidence of white mold later in the season.