Really Late Planted Soybeans
DR. ANGELA MCCLURE
JACKSON, TENN.
Farmers intended to plant about half of the 2015 soybean crop during June, but rains and flooding have delayed planting into July for some of those acres. I have had a number of calls about management practices for really late planted soybeans since it looks like some folks will not be able to get back in the field until mid-July.
We have limited late planting data, but soybeans planted as late as July 30th can make some yield before an October 23rd freeze. Because we are looking at a very compressed growing season, our goal should be to make pods and seeds as quickly as possible. Realistic yields at best may only be in the upper 30 bushel to low 40 bushel range.
Consider planting an early MG4 or late MG3 variety once we hit mid-July. Conventional soybean seed is cheap and a longer maturity bean will make some yield planted late. But, when we planted as late as July 30th, yields were below 30 bushels with determinate soybeans. Yield decrease was due to a larger number of immature seed at the time of the first killing frost. Yield and seed quality were best with a 3.8 and 4.2 bean and lowest with a 5.3 and 5.7 bean.
Manage inputs carefully. Reduce costs by cutting seed treatments, and scout and spray for insects and diseases only if needed. Generics, generics, generics. Note: really late planted soybeans may be more attractive to corn earworm, stinkbug and a few other pests, so check fields periodically to make sure they aren’t overrun.
Narrow rows will canopy quicker and help with weed control. In our work we planted 180K on 30” rows and they did fine for us, but weeds weren’t an issue in our field. I would plant a healthy population to start with (160K to 180K) to help push height a little in the rows.
Our crop insurance late plant period for soybean ended in June. If you are wary of planting without insurance, check with your agent to see if partial coverage is an option when planting this month. ∆
DR. ANGELA MCCLURE: Extension Corn and Soybean Specialist, University of Tennessee