1. Use seed of at least 90% germination and of a variety with high-yield potential.
2. The use of fungicide-treated seed is often questioned for mid-May or later plantings. However, since germination and emergence will be slower in the colder soils of earlier planting, treated seed may help prevent fungal infection, especially in no-till systems.
3. Over-wintering bean leaf beetles will be attracted to and will feed on the young leaves of early-emerging seedlings before laying their eggs. The leaf loss arising from this feeding is usually not significant unless the beetle population is large (see this week's story on managing bean leaf beetle). If those early appearing beetles carry bean pod mottle virus (BPMV), however, they can transmit that virus to the seedlings they feed on. Later arriving beetles feeding on early infected seedlings can then transmit the virus to other plants. If over-wintering beetles carrying bean pod mottle virus are common in your area, you may need to treat your early planted seed with a systemic insecticide in order to capture the yield benefit accruing from early sowing.
4. Worried about late spring freezes? For a near-zero risk, first identify the calendar date of the last-ever (historical) killing freeze date in your area (example: May 13 in Lincoln). Then, plant just early enough so that the soybean cotyledons emerge from the soil only on or after that freeze-free date. (For example: an April 28 planting date works in Lincoln).
5. Finally, don’t move the planting date too early into April. An unusually warm spring can lead to the first emerging leaves sensing a long night length and then sending an early floral induction signal. About 30 days later, the first flower will appear. If flowering is too early in vegetative growth, plants will not have enough nodes to support high yields.

Copyright 2006 by the University of Nebraska Board of Regents. All rights reserved.

Published by University of Nebraska-Lincoln Extension in the Institute of Agriculture and Natural Resources Cooperating with the counties and the U.S. Department of Agriculture.

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