So, you think mistakes with herbicides can’t happen to you? You think they only happen to people who are sloppy or because a custom retailer hires someone who isn’t well-trained? Well, here’s proof that it can happen to anyone.
The grower who farms the field pictured here is extremely conscientious. He’s been known to call his seed dealer multiple times in the same day if he isn’t 100% sure that a hybrid he’s preparing to plant, say in a plot, is tolerant to the herbicide he intends to use. If he can’t reach the seed rep, he looks up the hybrid information on the internet.
So how did he spray glyphosate on this field of conventional corn, wiping out all but a few stalks, which were obviously tolerant? It was simple miscommunication between him and the partner who ordered seed. The applicator thought all their corn was tolerant to one herbicide or another. And the partner forgot to tell him that he bought a few bags of conventional corn without herbicide tolerance.
In the end, the applicator took the blame. He took time to carefully check other hybrid labels, but not that one, because he thought it was Roundup Ready corn. It wasn’t!
“Mistakes are still going to happen unless you constantly double-check and keep tabs on everything you’re doing,” says Bill Johnson, Purdue University Extension weed control specialist. “It’s just a fact today. We’ve had herbicide-tolerant corn now for many years, but if you don’t continuously check and double-check hybrids versus herbicides, you can spray the wrong thing in the wrong field and wipe out the crop.”
In the case documented in this picture, the farmer replanted with herbicide-tolerant corn once the first crop began to die and he tracked down what happened. He shifted to an earlier hybrid, and even though it was planted in early June, it still made 175 bushels per acre dry corn.
However, here’s the rub: Fields on either side of it, planted about when the first crop was planted, yielded about 215 bushels per acre. That’s a difference of 40 bushels per acre. At $4 corn, that’s $160 per acre. Add in roughly $90 per acre for seed cost for planting the second time, and that’s $250 per acre.
There’s a hidden lesson, here, on top of the obvious one: Know what is planted where, and check labels both on the hybrid bag and the herbicide as many times as it takes to get it right, Johnson says. Also: If there wasn’t another field for comparison, you wouldn’t realize how big of a hit you took from spraying the wrong herbicide. On its face, 175 bushels per acre seems like a reasonable yield. But when compared to what it could have been, it falls short.
It’s the same logic that Extension specialists follow when advising how to include check strips in fields to try a new product or practice. Ideally, replication happens within the same field, but that’s not always possible. However, without some form of comparison, you have no idea what you’re gaining or losing from one practice or product, Johnson concludes.