Rice Weed Control 101

Command Is Not A Broadleaf Herbicide

Andy Kendig, State Extension Weed Specialist

Printed/Posted with permission of Mid America Farmer Grower

As Command's rice label nears, some very basic questions have been emerging from rice growers. Most recently, a grower asked, "If I put Command out right after I drill my rice it'll take care of everything right?" Wrong.

A number of rice growers will be caught because Command is different from typical rice herbicides. Even though Stam, Arrosolo, Facet and Bolero are often called "grass herbicides" these herbicides also control a large number of broadleaf weeds. Command basically controls one broadleaf weed: velvetleaf. But, coffeebean, indego, nutsedges, morningglories and most other broadleaf rice weeds ARE NOT CONTROLLED. This is not a major limitation- for several years, growers have used Prowl alone in delayed preemergence programs which releases most broadleaf weeds. If you have never used such a program, visit with someone who has. Again, nothing is wrong with Command, the problem is that we often forget to give broadleaf credit to traditional rice herbicides.

How do you control broadleaf weeds? Check your favorite weed guide. Grandstand, Storm and Londax all have their place. Grandstand and Storm will probably need to be sprayed 4 to 7 days ahead of flood up.

Next question: "And it won't hurt my rice either, right?" As some folks might say, "that depends upon how you define the word "hurt". On a silt soil there is a very high probability that your rice will have a bright white color for the first couple of weeks. In fact, there have been occasional instances of stand reduction. However, we have yet to observe a yield reduction from the targeted rates. Of course the favorite joke has been that at $7.00 per acre, maybe it's just light green. Gumbo folks, may not see any white rice.

Do you need Disyston or some other kind of safener like on cotton? No, almost all Command research has been conducted on regular rice seed. Disyston-treated rice was tested and there was a little less white, but the bottom line is that a safener is not needed.

When is the best time to put it out? I'm not sure that there is a best time. But we're recommending true preemergence, immediately after planting. There is nothing special about that time EXCEPT THAT TRUE PRE IS SIMPLER THAN DELAYED PRE. We commonly spray cotton herbicides behind the press wheel, why not mount a broadcast boom on the drill? Pre-plant incorporated has caused more whitening and stand loss. Delayed PRE has bee equal to PRE and in some cases POST applications to spiking rice have killed some germinated grass weeds- but this result has been less consistent. Postemergence tank mixes of Command and Stam have caused rice to turn whiter and remain white longer and this application may never be approved.

What about flushing? Command does not need flushing for weed control. An activating rain is nice, but Command needs less activation than most preemergence herbicides. Beware, Command may be like Prowl where flushing can actually reduce weed control. If rice has to be watered, flush, but if you get half-way normal rains Command won't need any flushing to work.

Does Command provide perfect grass control? There have been some instances where we had some grass escape on heavy soils under heavy rains. No herbicide is perfect- Command included- but it's residual activity and dependability are in the upper 50% of rice herbicides.

Finally, what's it do to red rice? Sorry, but it doesn't turn red rice white. Basically there is no effect, although it can turn the leaves white. Red rice is still botanically the same as white rice.

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