Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Seed production regions were hard hit last year by drought including Delmarva. Seed is in short supply and the quality is variable. It will be important this year to handle your soybean seed carefully. Be gentle with the seed, the seed coats may be thinner than normal and the cracks that form from handling may be avenues for fungal infection when the seed is planted. Most Delaware growers plant soybeans when temperatures are above 60°F which is favorable for rapid germination. At lower temperatures especially around 50°F emergence is delayed and fungi have an opportunity to infect since the cracked germinating seed is leaking nutrients that they can use. Once emergence takes place the plants become more resistant to infection. So the sooner the plant gets out the ground, the shorter the period that it is exposed to infection by soilborne fungi. Most seed will be or should be treated this season. Any seed that tests less than 80% germination should definitely be treated with a fungicide.