Here in southern Illinois it feels like a brisk fall day, the temperature at 7:00 a.m. was 55 degrees. I hope we aren’t setting a precedent for colder than normal temperatures. We really do not need an early September frost. As I drive around the Wabash Valley and its tributaries, it seems many of those acres wiped out by June floods have been replanted to soybeans. Most of those acres were planted between July 20th and August 1st. We still have a lot of time on those beans to have a chance at producing anything and an early frost would just add insult to injury.
Over the last couple of weeks I have spent a good deal of time trouble shooting late season issues in soybean fields. From disease and insect pressure to the biggest issue: resistant weeds. Many of the fields I looked at would have responded positively to an R3 fungicide treatment. However, with the economic climate and now very dry conditions, it was not a popular program with growers. Most are in cost-cutting mode right now, trying to keep expenses down on an already uncertain crop. The time for any real late season applications is now past, with several fields showing that “old look” as they prepare to mature.
I think this fall is going to be an eye opener for many on weed issues though, not only in our soybean fields, but also in the corn fields that will be rotating to beans next spring. It is pretty easy to drive around anywhere in the Midwest and see the waterhemp, marestail and giant ragweed poking their heads out of the soybeans. But if you want a real picture of what you will be dealing with next summer look in your cornfields now.
I am finding a significant number of pigweed species and giant ragweed that are just under the canopy where you can’t see them without walking the fields. These are making a ton of seeds that we will deal with next spring and summer. I’m sure by the time we are done running the combines this fall we will also see some marestail germinating and ready to over-winter.
A good fall burn down program or the use of an appropriate cover crop will help get us off to a good weed control start for 2016. Since we are covering such a large geography I will simply talk about practices, not products. Many of our residual herbicides are getting the blame for short beans and poor root development. While I agree it was an issue early on, I believe most of the injury that we are seeing now to be from saturated soils, compaction and poor conditions for root development. Did some of the injury occur because of the herbicide? Probably, but we must look at the whole package on weed control. Any weed resistance management program must contain a good, multi-mode of action soil residual herbicide combination. Even Liberty® works better over a residual.
Cover crops are a good solution if you do your homework and get them planted at the optimum time. Aerial seeding is a good option for many with later planted crops. Fall burn down is very popular as well, but don’t get carried away with high cost residuals in the fall, a little metribuzin still goes a long way. The choice of burn down products is also important: 2,4-D, dicamba, glyphosate and paraquat are all good choices for a fall application.
As with anything, do your research. Your farm has unique issues and I don’t believe in a “one size fits all” approach. Between now and when harvest kicks off we need to develop a plan for our 2016 crop and knowing what the end of this 2015 mess is leaving us is an important piece in that puzzle.
Mike Wilson is a Specialty Products Marketing Coordinator at Wabash Valley Service Company. For over 20 years, he has been working with farmers in ten counties in southeastern Illinois to improve economic yield in soybeans, corn and wheat. Mike has been a CCA since 1994 and is looking forward to being a part of the Soy Envoy program.