With hail and wind damage and saturated or flooded fields across eastern Nebraska, some growers are considering whether replanting is warranted and, if it is, what cropping options would be best for the delayed planting date. In some areas producers haven’t even been able to finish their initial planting due to wet field conditions.
Before making any decisions regarding replanting, contact your crop insurance agent about your insurance coverage and options. If you do replant, discuss whether you want or need to insure the second crop. Also consider, herbicides already applied to the field and their replanting restrictions; availability of the seed and traits you want; and approximately when you expect to be able to reenter the field and the remaining light and heat units in the season.
Replanting Soybean
Much soybean stand loss can occur within a few days under flooded conditions and warmer temperatures. This loss will increase if silt covers the leaves or buries whole seedlings. If hail breaks off the plants below the cotyledons, plants will not survive; however, if the leaves are merely tattered, full recovery is likely; however, injured plants have an increased risk of delayed problems from pathogens.
If there are more than two surviving plants in two feet of 15-inch rows or four feet of 30-inch rows, replanting isn’t likely to increase yields. Full season varieties can be replanted until June 15. After June 15, consider planting a variety that’s half-step down from the maturity group you usually plant. For example, if you normally plant a Maturity Group 3 variety, after June 15 you may want to drop to a 2.5 Maturity Group. With delayed planting of soybean, consider planting at a higher density. This should increase podding and thus, increase yield.
Also assess seed availability. Contact your seed dealer as soon as possible and expect to be a little flexible about what you’ll use if your preferred varieties aren’t available. UNL Foundation Seed still has quality seed in all its offerings, according to its director, Jeff Noels.
If soybean is to be planted into a field of damaged corn, check with your seed dealer regarding recommended herbicides that would work well under this circumstance. If the corn was not glyphosate-resistant, glyphosate is an option. Also, consider the residual effect that herbicides applied for corn will have on soybean.
Replanting Corn
Corn from germination to the 6-leaf stage can survive four days of flooding if air temperatures are below the high 70s. Corn should recover well from hail damage if younger than the 6-leaf stage. If the surviving stand is more than 60% of the intended stand, it is better not to replant in early June. Plants have the capacity to compensate for reduced stand, primarily by producing larger ears. For example, a surviving stand of 16,000 planted before May 5 is expected to provide a higher yield than replanting at 30,000 seeds/acre on June 12.
Research studies conducted at UNL’s Panhandle and West Central Research and Extension centers found that yields dropped precipitously when replanting corn after June 15, even with a shorter maturity hybrid. Producers who feed their own corn could go to a 100-day corn and get good plant production. The research indicated that pound for pound it produced as well as longer-term maturities that produced higher test weight ears. In research at the West Central site, grain yields dropped 25-30% between June 16 and June 23, even with shorter maturities.
Dave Varner is an Extension Educator with the University of Nebraska-Lincoln Extension office in Dodge County. Dave may be contacted at 727-2775, 1206 West 23rd Street in Fremont, or at dvarner1@unl.edu
