Soybean varieties in NC do not tolerate wet feet- or more precisely wet roots- very well. When farmers experience excessively wet springs and summers, especially in the eastern and northeastern part of the state, chronic wet roots cause slow grow-off, poor leaf color, and spindly plants. Getting yields greater than 45 bushels/acre under those conditions is a challenge, even when all other production aspects are perfect. New discoveries in Arkansas and Missouri, where flooding and wet feet are even more common than in North Carolina, are promising hope that this problem can be overcome. Some soybean varieties have been shown to handle extra water much better than others in the field. New Mid-South varieties now on the way appear to be even better than the existing stocks.

The big question for North Carolina farmers is, “will this new Mid-South technology really show a payoff in our NC fields?” Given that the past three seasons have been very wet in NC, we certainly hope so! The North Carolina Soybean Producers Association is joining forces with the USDA-ARS and N.C. State University to explore the potential of this new flood tolerance technology. The outdoor laboratory for flood tolerance research in NC is the Tidewater Research Station. Results thus far have revealed the surprising result that several breeding lines developed by the USDA Soybean Breeding program on the NC state campus have good levels of flood tolerance.

These newly identified materials are on a par and perhaps better than flood tolerant material from the Delta. Two high-yielding flood tolerant breeding lines are proposed to be released in 2021 from USDA in NC. USDA breeding lines N11-352 and N10-792 have been identified over the past three years as high yielders in maturity group (MG) VII regional trials across multiple years and environments. These lines also appear very flood tolerant in multiple years of testing in NC. N10-792 traces 12.5% of its pedigree to slow wilting PI 416937. In 2020, N10-792 and N11-352 received two of the lowest flood scores, indicating they were the most flood tolerate lines evaluated. Both breeding lines were developed through multiple cycles of breeding and selection for improved yield in the tidewater area of NC. Other promising lines have also been identified that when flooded for 7 days can yield up to 60% of the yield when grown under nonflooded conditions. Yields of currently available soybean varieties can be as low as 20-30% of the yield of when grown under non-flooded conditions. So, we are making progress in developing flood tolerate varieties for NC farmers