Researchers at North Carolina State University are looking to cultural practices as a way to help control Italian ryegrass in wheat.
In 2014 and 2015, N.C. State scientists examined how row spacing and tillage practices impact Italian ryegrass in wheat. “We didn’t see any result with row spacing. If Italian ryegrass is going to come in, it’s going to come in regardless how dense that wheat is,” said N.C. State Extension Weed Specialist Wes Everman, speaking the Northeast Ag Expo Small Grain Field Day in Elizabeth City. “The tillage practices are where we saw some real differences.”
The research was conducted in two locations in North Carolina over two years. A number of different herbicide treatment programs were used in no- till and conventional tillage plots. Everman explained that pre-emergent herbicide applications only, spike applications, post-emergent applications only and both pre-emergent and post-emergent applications were all examined.
“In both years of the study, where we had the tilled plots, we saw less ryegrass. We saw better control with tillage We chalk this up to that tillage encouraged a flush of ryegrass to come up. We tilled the ground and that ryegrass wanted to come right up with that wheat. By putting out a residual product early, we caught that flush,” Everman said.
Yields were higher when both pre-emergent herbicides and post- emergent herbicides were used rather than post-emergent herbicides alone. For example, Everman noted that a treatment of the herbicide Zidua followed by the product Axial did better than a mix of Zidua plus Axial.
“Letting that ryegrass compete early and not getting it controlled cost us 20 bushels per acre. It points to me that we need to be putting out these spiked treatments to set us up when we know we have bad ryegrass infestations. Early season competition is really going to impact our yields on the back end,” Everman said.
Everman noted that the tillage was not deep tillage. The soil was tilled just enough to stimulate germination. But Everman said the research makes it clear that all herbicide programs are more effective in a tilled system.
“It’s not going to be every acre. I’m not trying to anger no-till farmers, but when you have a really bad ryegrass situation I think the lesson is to shift things,” Everman said. “If you do the same thing over and over, and the same is true with herbicide resistance, Mother Nature finds a way to beat us so the only way to succeed is to mix things up. Throw Mother Nature a curve ball and get the upper hand every now and then.”