We are getting some good looks at our weed research plots now and have some interesting stuff. We are now evaluating soil-applied treatments and postemergence treatments made up to about four-leaf rice and grass. Both Ricestar and the new herbicide Clincher are giving good control of the small grasses.
Most reports from the field are giving passing reviews on Ricestar. Nobody seems to be doing cartwheels over Ricestar's performance like they did with Command the past two years. However, most seem to feel it is doing what they need it to do.
I have had some calls on failures under dry conditions and on big barnyardgrass. Those are to be expected.
The tank work we have done with mixing Ricestar or Clincher with the broadleaf herbicides on small grasses has not shown a lot of antagonism. Based on previous work, my guess is the tank-mix treatments we are now applying to larger grass will.
The hot recommendation in the field now seems to be to take out some Ricestar and add Whip back in for control of larger grasses. These treatments originated out of some of last year's thesis work by Nathan Buehring (a student supervised by Ron Talbert and me).
There are a lot of recommendations being made with a small amount of data — none of which was earthshaking. As long as the recommendation is being made to keep the total amount of Ricestar plus Whip at 17 ounces of product, it is unlikely any huge differences in grass control will be achieved by replacing small amounts of Ricestar with Whip.
In Nathan's study last year, end-of-season ratings on barnyardgrass and broadleaf signalgrass for 17 ounces of Ricestar and 13 ounces of Ricestar plus 4 ounces of Whip were identical at 56 percent for barnyardgrass and 68 percent for broadleaf signalgrass. The grasses were sprayed in the early tillering stages. Rice yields resulting from the two treatments were statistically equal.
One of the herbicides that has looked much better for us this year has been Aim. By itself, it has looked good on small broadleaf weeds, including smartweed, and very good across the board when mixed with propanil. It has also been one of the treatments that has looked good mixed with Ricestar or Clincher. The Aim formulation seems better this year, although we still have to be careful to get it to go through our small plot equipment.
One of the things that really stands out in our plots this year is the difference in rice tolerance between the current Clearfield rice varieties (CL 121 and CL 141) and the new variety that is coming. With CL 141 and the new one planted side by side and using Newpath rates up to five times the labeled rate, there is a daylight/dark difference. This test will make good slides for the winter meetings.
We are getting about our normal amount of injury with labeled rates on the CL 141 and essentially none at 5X rates on the new (potential) variety.
Ford Baldwin is an Arkansas Extension weed scientist.
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