Ford Baldwin

May 16, 2008

4 Min Read

Thus far there has been no consistent theme to my telephone calls. It has been a totally crazy year with everyone trying to get a rice crop in the ground any way they can.

I hope we are not sitting on a weed control time bomb ready to go off at any time.

A lot of growers have been able to keep sprayed up on soil-applied herbicides. In those cases, the abundant moisture in most areas should result in excellent weed control.

In a lot of other cases, growers have just had to get a crop planted any way they could. Some of those fields may present some interesting weed scenarios later. One thing is obvious — this will not be a “normal year.”

I stated last week and will do so again: if you do not have residual herbicides activated and grass is coming, hit it quickly and hit it hard.

Also, if you feel you need help, the earlier you call someone, the easier it will be to help.

In Clearfield rice, I like timing the first postemergence application of Newpath to two-leaf to three-leaf red rice. Usually in a program where you are using two postemergence applications, timing the first one at two- to three-leaf red rice and the second one just prior to flooding works well.

If you used a soil-applied Newpath application, time a postemergence application to two- to three-leaf red rice and see where you are. In the Clearfield hybrids, evaluate the fields very carefully just prior to flooding. If there is any red rice present or if there is any doubt that previously sprayed red rice is going to die, I suggest making a Beyond application right then.

The RiceTec cutoff on Beyond applications on the hybrids is at panicle initiation. We know from previous experience that the red rice normally will not be out of the rice canopy by panicle initiation. Therefore, if you have escapes, by the time they emerge out of the canopy it will likely be too late to spray them.

While the Clearfield hybrids may have acceptable field tolerance to Newpath and Beyond, the fact they have less tolerance than the Clearfield varieties makes it difficult to get as aggressive with the herbicides as we would sometimes like to. This raises stewardship concerns. If you have late escapes and cannot treat them, the likelihood of out-crossing increases tremendously.

A lot of research still needs to be conducted in Clearfield rice. It appears now that the amount of university weed science research on both efficacy and out-crossing involving the Clearfield hybrids will be drastically reduced due to an impasse between university scientists and industry over paperwork requirements. In my opinion, this is not in the farmer's best interest.

Quite often in Clearfield rice, the weed control decisions are not as much what to do with the red rice, but what to add for the other weeds. There is an excellent fit for quinclorac and a lot of interest in Clearpath. The Facet component will increase the Newpath activity on barnyardgrass and broadleaf signalgrass and provide some residual control of coffeebean and indigo.

One of the most frequent questions I get about Clearfield rice is on indigo control. In addition to Facet, Permit has good activity and at higher rates can provide some residual control. There is a fit for Strada in Clearfield rice for coffeebean and indigo control as well.

Aim can be a good tank mix partner and is particularly good on small groundcherry. It is weak on indigo unless you add another herbicide for that weed.

Another tank mix partner that always looked good in Tomilea's early Clearfield research was Regiment. Regiment will make sure the barnyardgrass is not missed and it has a lot of broadleaf activity.

An often overlooked tank mix partner for Newpath is just propanil. Three to 4 quarts of Stam, Super Wham or Duet plus Newpath is a very broad spectrum postemergence mix, but it has no residual activity except for what the Newpath provides.

There is no one best tank mix for all situations. Tailor the mix to the weeds you have and the need for residual control.

About the Author(s)

Ford Baldwin

Practical Weed Consultants

Ford Baldwin served as a weed scientist with the University of Arkansas Cooperative Extension Service from 1974 to 2001. During that time he conducted extensive applied research trials in rice, soybeans, cotton and wheat, and developed weed management recommendations and educational programs for farmers. Since January 2002, Baldwin has been a partner in Practical Weed Consultants with his wife, Tomilea.

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