is part of the Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Serving: Central

Evaluate success of this year's weed control in rice

I have heard a lot of farmers comment along the line of “What happened to my weed control? It started so good.” I still think that overall we have the cleanest rice crop we have had in a while.

Folks in north Arkansas (north of Hwy. 412) seemed to have more trouble getting barnyardgrass under control than others. That part of the state was drier earlier than the rest of the state and that caused some problems.

In my weed control talks I tell farmers about the importance of herbicide/moisture relationships. It would be hard to rank that relationship ahead of application timing in importance, but if you combine the right herbicide/moisture relationships with proper application timing, you can knock weed control home runs.

Timing soil residual herbicide applications just ahead of a rain or flushing and timing postemergence herbicide applications close behind a rain or flushing will make you smile almost every time.

In most cases, Command this year worked the best that I can remember since perhaps the introductory year. That saved a lot of growers at least one herbicide trip across the field.

When we hit a wet spell just after much of the rice was planted, the weather forecasters were pretty accurate in their predictions. Several consultants called me about following Command with Facet even though the Command was activated and working well and they didn't have a lot of small grass emerging. Because of the timely rainfall, that was an excellent program this year.

The guys who got Command out in front of one rain event and a Facet application close behind in front of another rain have smiled all year.

The key to having the most efficient rice weed control programs is taking maximum advantage of soil residual herbicides. Sprangletop and broadleaf signalgrass are relatively easy to get back under control if early mistakes are made.

However, if barnyardgrass starts tillering and gets on a roll, it can be very expensive, very difficult and sometimes even impossible to get back under control.

Every year I get calls from growers who have thrown the “kitchen sink” at big barnyardgrass and failed to control it. This grass species is by far the most-adapted for competing with rice and it seems it is becoming even more adapted as we put more herbicide pressure on it.

I do not know of any documented cases of barnyardgrass resistance to Command. It would not surprise me if it happened. On the other hand, barnyardgrass resistance to both propanil and Facet are common in Arkansas.

Resistance of the barnyardgrass genus, Echinochloa, has also been documented in other states and other countries for the other major classes of grass herbicides that we use.

The cleanest fields this year and the ones with the lowest herbicide costs are those where grasses were controlled early — often before they emerged.

Another program that worked very well this year was following Command with either propanil or Ricestar HT with either more Command or Facet. Where these treatments were made early and followed by rain, they worked very well.

Now is the time to evaluate how you did this year. If the field is clean, you are likely happy. If not, it is a good time to think about finetuning the program for next year.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.