So far, this summer has been a lot different than those we had from 2007 through 2010. Those were wet summers with lots of difficulty in getting soybeans planted. However, it has been eerily similar to last summer which turned out to be very hot and dry. We have lucked out and gotten some rain in June that certainly has helped but we are a long way from being over this crop year hump. Anything can happen and ,hopefully, those happenings will turn out to be good.
I have had a couple of calls about how late soybeans can be planted in this area. I don’t think there will be many late beans out there but the subject is important enough to warrant another article this year. I can’t give an exact prediction but there is some information from the KSU Ag Research Center in Parsons that does shed some light on how we can expect things to play out as it relates to soybean maturities and planting dates.
The research information was generated by Ken Kelley, retired Crops Research Agronomist at the center. His work was done back in the early to mid eighties and, though the research was done quite a number of years ago, I think it is still valid. Ken’s research addressed the issue of how the planting date affected the yield and date of maturity for the various soybean maturity groups.
Ken used five different maturity beans at five different planting dates over a period of five years.
The beans ranged from a late group three to a late group five. The planting dates ranged from a late May planting to a mid-July planting. The most striking thing is that yields of all maturity groups at different planting dates did not vary that much. However, the yield of all the maturities dropped considerably in the mid-July planting.
A very real problem quickly becomes evident when looking at the affect of the later planting dates with full season varieties.
The date of maturity of the group five soybeans is pushed back into late October and even the first half of November.
This factor brings two things to mind.
First of all, many farmers like to plant wheat after beans. If the beans can’t be harvested until November, then planting to wheat may not be possible.
Secondly, later maturing beans planted late may be subject to early freeze damage. We have seen how adversely early freezes can affect our later planted longer maturity beans.
The conclusion from this information is as follows.
Mid group fives can be safely planted through June 20 and early fives can be planted as late as July 1 without serious risk. However, after July 1, farmers need to consider dropping back to a late four. After July 10, you probably should not be planting beans, but if you do, use an early to mid group four.