I, like many of you, have watched as pigweeds have slowly re-infested many soybean fields that started off clean this year. I have talked to many growers who have spent a small fortune fighting Palmer amaranth this year only to see many fields still grown up.
There is little money left for hoe crews and no chemical options remain. Many of these fields will be combined, surely spreading the weed — not only in these fields but in others that the combine goes into later. I do not blame you for cutting these beans; there is money out there. Most fields are clean enough and were clean enough long enough that yield may not even be affected.
However, there will be plenty of pigweed left for next year to deal with. I’ll give you some thoughts about what we learned this year and a few suggestions for next year.
My first observation in the pigweed fight is that wide rows simply do not work. Whether you are staying in Roundup Ready or going LibertyLink, failure of the soybeans to canopy means that pigweed will continue to germinate all year long. I know that this may mean that you have to change the way you farm, but you must do what you can to narrow your row spacing.
People have asked about post applications of residuals like Dual and about hoods. Dual is a good idea and can help. There isn’t much else to pick from in terms of post residual herbicides for soybean because most of our pigweed are ALS-resistant. So products like Scepter and Classic don’t help much. As far as hoods go, it’s a good theory, but I am not sure what to tell you to put in one.
In side-by-side studies this year, our drilled soybeans were on average 10 to 20 percent cleaner at canopy than wide rows with similar or exactly the same herbicide programs. Drilled rows are best, if you must stay on beds. I would consider trying to get two or three rows per bed instead of one.