Rice cutgrass is an emerging Arkansas weed problem — particularly in zero-grade, reduced tillage and water-seeded crops.
“I’m continuing to get many calls on this,” said Bob Scott, Arkansas Extension weed specialist, at the recent Southeast Branch Station field day in Rohwer, Ark. “Problem acres seem to eek up a bit more every year.”
Scott passed around a small pot full of the grass for those on the tour to handle.
“If you’ve never seen or held it, check this out. When you grab at it, it will pull against your skin.”
Normally, the weed is relegated to ditch-banks. But when tillage is taken out of the picture in continuous rice fields, it emerges as a problem.
Another big reason cutgrass has become a headache: Command, Ricestar, Clincher, Regiment and other herbicides have very little activity on it. Prior to Clearfield rice coming on the scene, “we had some success with 1- to 1.5-gallon rates of glyphosate per acre in the fall. That fall application is an attempt to reduce cutgrass for the following spring.”
Since Clearfield’s arrival, farmers with the weed have reported two applications of Newpath at 4 ounces post “are pretty good. Many times, in order to gain control, a Beyond application is also needed. But outside Clearfield, you’re left with a major application of glyphosate in the fall.”
As for new herbicides, there’s a “definite need to bring back Collego. We thought it was back this year.”
A small company was formed intending to bring back a similar product under the name Lockdown. The company had EPA approval “but had some manufacturing troubles and ended up not producing enough material to meet demand.”
Scott said a few fields were treated in a test run for Lockdown. It performed “a lot” like Collego.
“If everything goes well, it should be available next season. I get a lot of calls on joint vetch late. We need a consistent product for that weed and this could handle it.”
Regardless, don’t leave joint vetch late. “Get it with Facet pre or a good pre-flood broadleaf program. Once that vetch gets big it’s very hard to control.”
Much of Scott’s research focus has shifted away from grasses to the broadleaf spectrum.
“That’s because Command, Ricestar, Clincher, Regiment and others have come along. The barnyardgrass issues have been resolved for the most part.”
Now, companies seem intent on filling in the gaps on the broadleaf side. Scott and colleagues are currently investigating a few new products from Valent and Dow.
“Those companies both have new compounds that are still a ways from market but they’re in the research pipeline.
“We’re also in the third year of evaluating (Strata) from Italy. The company says it should be available in 2007.”
When research first began with Strata, it was believed to be a grass compound.
“We checked it on barnyardgrass and essentially wasted a year of research. It isn’t a material for that.
“It turns out Strata acts a lot more like Permit. Most of our comparisons this year have been done against Permit. I like it in all the same combinations and tank-mix partners that Permit is good with. But Permit is better on yellow nutsedge.
“The company realizes that, though, and they’ve said it will be priced competitively. If you don’t have yellow nutsedge, it should be an option. I told them if they made Strata cheap enough, growers would figure out how to make it work.”
Editor’s note: to view this story unabridged, see the Delta Farm Press tabloid.
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