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Mississippi entomologist updates pest thresholds. Aims to save producers money. Three-cornered alfalfa hoppers, bean leaf beetles, stink bugs.
ANGUS CATCHOT, MISSISSIPPI entomologist, presents recommendation tweaks and new research information at the mid-January Cotton and Rice Conference. The tweaks, he says, “should save you some money.”
One of the benefits of farming in the Mid-South is the amount of cooperation between researchers across state borders. That ultimately saves area producers money.
“We work really close together across the Mid-South – Arkansas, the Missouri Bootheel, Tennessee, Mississippi and Louisiana,” said Angus Catchot, Mississippi State University entomologist, at the mid-January Cotton and Rice Conference in Tunica. “In fact, before this session began we were in here planning future projects.”
That cooperation allows a lot of data to be gathered in a short period of time. “We can get a ton of trials out compared to if we were working alone. We’re constantly evaluating thresholds, looking at new chemistries, trying to keep up with resistance. It’s a constant struggle.
“Some of the things I’ll present today are changes we’re making in the Mid-South states.”
Three-cornered alfalfa hoppers
Several years ago, there were many questions about three-cornered alfalfa hoppers (TCAH).
“We’ve gotten a lot more data since. One thing I noticed very quickly was we can chase TCAH with two and three sprays. What I saw across the state where we were making application for TCAH, we were killing them. They aren’t hard to kill. They’re very easy to control but seven days later they’ll re-infest the field.
“Before you know it, we’ll have three hopper applications between R-3 and R-5 and have flared worms leading to more problems.”
A lot of hopper research was done across the South, said Catchot.
“One graduate student was completely devoted to it. One thing he found – and I’m not discounting early-season hopper damage on small soybeans, main stem girdling – is we can’t show a yield loss from treating TCAH. It used to be that the threshold was one per sweep: 25 for 25 sweeps. So, we made a change and gone to two per 25 sweeps: 50 for 25 sweeps.”
Based on the data, most entomologists “feel you could go to three, four or five (per sweep). But currently, what we’re saying is the threshold is two, or more, per sweep.”
One of the recommendation changes for 2014 is to terminate treatments at R-6, “even if you reach that two or three hoppers per sweep. We’ve been making late-season hopper sprays and all we’re doing is flaring some of the pests that can really cause yield loss. The reason is when you begin spraying pyrethroids across the field, you’ll create a problem where one didn’t exist previously.
“Doing this will definitely save you money.”