Although this is at the beginning of the period for measuring rainfall, continued wet weather should favor germination of the sclerotia. Scleroia are the black, hardened structures that allow the fungus to survive for many years in the soil, and the ascospores are responsible for infecting the plants during times of susceptibility. Ascospores only infect flowers, so the production and release of ascospores is important only during flowering. In both soybeans and dry beans, the earlier stages of flowering are more important than later stages. Therefore, chemical controls are economically effective when applied at the earlier stages of flowering.
Bloom is defined as the percent of plants with at least one open flower.
The application of fungicides to soybeans has provided inconsistent control, with yields ranging from zero to 25 percent above the untreated controls. As with fungicides, the results have been erratic. The best management practices are to select varieties with moderate to high levels of resistance, and to grow soybeans in rows of at least 21 inches to 28 inches in width. Weather news Jeff Andresen Agricultural Meteorology Geography Fair and dry conditions are expected for the coming weekend as an area of high pressure settles in across the region. A large upper air-ridging pattern currently across the western U.S. is forecast to slowly move eastward towards the Great Lakes by early next week.