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Watch rice for diseases, stink bugs

Jul 12, 2007 9:31 AM, By Ford L. Baldwin
Practical Weed Consultants, LLC.

The rice crop sure seems a lot further along than normal. This has caught a lot of growers off guard on growth stage for timing midseason herbicide applications.

At the time of the year when I normally get a lot of calls about the consequences of applying herbicides after rice is past the 0.5-inch internode elongation stage, I am getting calls on “what is going to happen if I apply a herbicide after the rice is booting or later?”

No answer is usually good. When things get to this point, the cows are simply out.

There are a couple of other things that you do not want to let slip up on you. We have had a lot of cloudy, humid and wet weather while the rice has been in the reproductive growth stage. There is a lot of disease pressure down in the canopy in some of the fields I have been in.

This is not my area of expertise and I am not predicting a worse-than-normal disease year. There is plenty of expertise in the University of Arkansas system and among crop consultants to help you in this area. My concern is that you do not get past the point of no return on diseases with the crop being ahead of normal and conditions being right to favor diseases.

The other major area in which you want to keep your guard up is stink bugs. The rice crop in general is one of the cleanest I can remember from a grass control standpoint. Stink bugs like barnyardgrass, so hopefully less grass pressure will mean less stink bugs.

However, I have had reports of a lot of stink bugs staged up around the edges of fields. No one knows whether this means they are just waiting on the rice to head or whether they will be gone when it heads. Again this is not my area of expertise.

I do know the only way to know if you have a problem in an individual field is to scout. The best way is with a sweep net.

The University of Arkansas thresholds are 9 per 25 sweeps with a net or 1 per foot of row on a shake sheet. If stink bugs are at threshold levels, spray them.

Rice is susceptible from the bloom stage until maturity. My concern is that you protect the crop from a quality standpoint.

I am constantly asked, “How does the rice crop look across the state?” That can be dangerous because you are asking a guy whose training is in how to kill stuff. I can say, however, this year’s crop sure looks good from a weed control standpoint. Normally a field that is free of weeds looks good to the eye.

Obviously there are a lot of other factors that determine how it will turn out, but if it is free of weeds and you keep the diseases and stink bugs under control and you keep it flooded, that is about all you can do. The remaining factor will be the weather.

From a weed scientist’s standpoint this has been a strange year. However, for the farmer it has been good. Weed control was pretty easy for the most part. I have often said, “As the Command goes so goes the weed control season.” Facet also stepped up big this year.

The key to weed control is residual herbicides and tying herbicide activity to moisture. If you ever let barnyardgrass get to the point you can not kill it all with the first postemergence application, you are in a dog fight. If it gets to the point where whatever you use postemergence gives you only 80 percent control, that other 20 percent will give you fits and cost you a lot of money.

The herbicide drift situation so far this year has been much better than last. While drift is much more evident early on seedling rice, the real susceptible time for glyphosate, Newpath and Beyond drift is during the reproductive stage form green ring thru heading.

Please be aware and careful and let’s continue to have a “good drift” year.

e-mail: ford@weedconsultants.com