Canopy management affects the activity of the white mold fungus each season. Early planting date, narrow row width, and high plant populations (>200,000 plants/a) all accelerate canopy closure and favor activity of the white mold fungus. Bushy soybean varieties and lodging also create a dense, closed canopy which favors white mold growth.

Dense canopies favor the growth of the white mold fungus.

Early planting can result in higher yields because the crop has a longer time to grow and mature. In the presence of white mold, however, the yield advantage can be lost.

The effect of early planting on white mold occurrence is one of timing. Very early planting (April or early May) may result in a closed canopy and soybean flowering just at the time when the apothecia of the fungus are forming. Severe white mold can result, especially in fields where the disease has occurred in the past, if soybeans are planted early (Table 1).

Table 1. Effect of planting date on white mold incidence and soybean at five planting dates in Wisconsin.

Soil Fertility and Plant Nutrition
High soil fertility promotes canopy growth which favors development of white mold. Manure applications are associated with greater white mold development. Avoid an application of nitrogen to soybean in fields with a history of white mold. This situation is probably due to greater soil fertility promoting excessive plant growth and dense canopy development.

A correlation has not been observed between white mold incidence and soil pH, percent organic matter, or nutrient levels in soil or plants.