By Brian Hefty
Darren and I talk often about how fungicide should be a standard part of your crop protection package in wheat and soybeans, but corn is a different story. Over the last few years we have run extensive tests on our farm applying almost every fungicide labeled in corn at both V5 and at full tassel with virtually no yield gain.
Now, before we go any further please understand that if you have a bad disease in your area, like gray leaf spot, you should definitely spray. You are also more likely to get a good return on investment if you are raising continuous corn, if you are planting susceptible varieties, if you have wet and humid weather conditions, if you have insect problems, if you have a history of disease issues in corn, if you are shooting for high yields, and if the price of corn is great.
Since our area hasn’t had major corn disease problems, and we’re drier and more arid than most other regions of the country, we just haven’t been able to gain yield, and I’m starting to get sick of trying. We’ve been able to make our corn look better and even stand better, especially when we’ve sprayed fungicide after hail. Yes, we’ve probably been able to combine a little faster because of this, so that’s worth something, but we just haven’t gain much at all in terms of yield.
The other key issue, in my mind, comes in the application cost. We have had to pay approximately $8 an acre to bring a plane in, and I would have no issue with that if we were gaining lots of yield. However, when we’ve tried half rates of fungicide for $6, we more than double our cost when the application charge is figured in. Also, we don’t condone half rates of fungicides in all situations, but it was something we have experimented with. Anyway, what we’re doing this year is using a self-propelled sprayer that should get over the top of our corn at full tassel. At least that will keep our cost down as we continue our trial work.
One other reason I personally believe we haven’t seen good yield response, even though lots of other farmers have, is we work hard on removing other stresses. We don’t have excessive soil moisture issues now thanks to tiling. We are using insecticide and traits to control insects in corn, so that’s not a problem. We use good pre and post herbicides so our fields are pretty weed-free. We have also greatly enriched our soils by building organic matter and soil fertility levels dramatically in the last 10 years. What I’m saying is that if all other stresses are minimized, maybe we just aren’t getting as many disease issues as others. I don’t know. All I do know is we haven’t gotten much yield response from fungicide application in corn. Maybe we will in the future, and maybe you will on your farm, so we will continue to research this in the coming years.