I have predicted that in the next five years we will be using several non-chemical weed control methods to keep our herbicide programs viable. I would go so far as to say that you will look back to today and say, “I never dreamed I would be doing this.” I also predict that farmers will come up with as many of these innovations as professors will — or at least come up with the ideas. It will not be because you want to do these things, but rather you will have to in order to survive.
I quote Dr. Steve Powles, my mentor in Australia, quite often. He was recently back in our country and I was fortunate to get to spend some time with him. We actually did the “Cousin Carl” radio show together and it was a blast. He talked at length about some of the things they are doing to reduce their soil seedbank numbers and keep them low.
That is going to be key to whipping the pigweeds. You must keep the pigweed populations low enough that 95 percent weed control only leaves a few for easy hand weeding. One of their innovations has been a chaff cart pulled behind their combines. The professor figured out that roughly 95 percent of the ryegrass and wild radish seeds at wheat harvest are in the chaff fraction. A farmer invented the cart they pull it behind to catch the chaff and haul it along with the weed seed out of the field.
Another simple thing they do in place of the chaff cart is just divert the straw and chaff into tight windrows behind the harvester so it can be burned. They have found they can burn most of the weed seed with that method.
One farmer has designed a $160,000 machine to destroy weed seeds behind the combine. There have been a lot of attempts at this through the years and most were unsuccessful. The farmer-inventor has worked closely with Dr. Powles’ group and they are encouraged this system will actually work and also hold up.
I realize I am losing it with age, but hold up on the e-mails a minute. I am not saying any of these methods would work for us. I don’t expect our farmers to flood the Port of New Orleans with chaff carts from Australia or even the weed seed destroyers — if they work. I don’t think burning would work for us in most areas for several reasons. However, these are examples of what some farmers have had to do to keep using herbicides in wheat and to survive. Our examples may be totally different.
His point is “do you think a 10,000- to 30,000-acre wheat farmer in Australia wants to pull a silly chaff cart behind his harvesters?” Of course not, but they have had to. My call a couple of years ago from the farmer who is working on an invention to pull pigweeds from cotton or soybean rows does not sound near as silly as it did then!
We can avoid a lot of this in our country with the right mixes of diversity — if we just will. I recently spoke at a meeting in the heart of our rice-producing area. The pigweeds are just getting started there. An excellent farmer came up and said he had pigweeds show up in three or four fields last year. He had an excellent plan in mind. He plans to put the field in corn this year and use conventional herbicides. He plans to follow with rice next year and then a year of LibertyLink soybeans before growing Roundup Ready soybeans again. I complimented him and then challenged him. My challenge was “why don’t you start a program like this in your clean fields as well?” That is the step we need to get to in the fields that do not have “the problem” yet.
The acreage forecasts for corn this year seem to be up. Take advantage of the conventional herbicide programs for pigweed control. Where the rotation is with rice there are still excellent opportunities for rotations with Clearfield rice, Roundup Ready soybeans, conventional rice and LibertyLink soybeans to get more diversity in both crops.
A first weed control step in all crops this year is “starting clean.” The warm winter has the winter weed complex “getting it,” which means spring burn-down herbicides need to go out earlier than normal — or now if you haven’t. It will likely take a two-shot approach. Start with something like a half gallon of glyphosate, 2,4-D and a residual. If marestail is in the mix add some dicamba.
There are lots of choices depending on the weed mix and crop to be planted. The main thing right now is just do something — and something besides glyphosate alone. You can then clean up what is left with a followup application if necessary. Just do not bump up against the plant-back intervals on the residuals you choose.