In rice Flooding still key to weed control

In recent weeks I've been writing about my life as a real in-the-field rice scout this past season. I'll wind it up with this column.

When Tomilea and I assumed our pinch-hitting role, both farmers still had about half of their rice to plant due to an extended wet period in the middle of planting. Most of their rice ground was heavy soil. Once it dried, they were planting in clods and getting late in the optimum planting window.

This was actually good for weed control because they had to flush as soon as possible after planting to get a stand. Actually we were lucky because both farmers would flush if we asked them to anyway.

Flushing is the subject of a lot of frustration calls I get during the season from consultants. The comments are typically along the lines of “Doc, I know what I need to use, but my farmer won't flush — do you have any suggestions?”

When it gets dry, postemergence herbicides are not going to have adequate postemergence activity and pre-emergence herbicides are not going to have any pre-emergence activity.

I liked starting out on the fields at planting because I was strictly on my own, but there was more pressure. On the fields we inherited that were ready to flood, I could blame any problems I had back on the consultant we were pinch-hitting for. On the ones I started with at planting, he could come in later and blame any problems on me.

My standard practice was to apply Command as soon as possible behind the drill and have them start the flush water. We were in a dry period, which meant most of the fields needed to be flushed again to get an optimum stand. This was a good thing from a weed management standpoint.

In most cases we just recommended a half-pound of Facet right in front of the second flush even though there was no emerged grass. Some may be thinking “Doc you have gone from rate cutter to pouring it on!” Keep in mind, the consultant had warned me that most of these fields had a history of heavy barnyardgrass pressure and they had a lot of trouble killing it once it emerged.

This was also evident in a few fires we had to fight in some of the earlier-planted fields.

The more I deal with barnyardgrass and work with others who do, the more I am convinced you had better kill all of it you can before it ever emerges.

The key treatments for achieving early barnyardgrass control are the residual herbicides and tank mixes of the residual herbicides with postemergence herbicides such as Ricestar HT or Super Wham. Both of these, when tank mixed with Command or quinclorac (Facet or Quinstar) early, can get you out of a lot of messes.

I also used some Regiment on some of the larger barnyardgrass, and it is obvious the new surfactant package has made a much better herbicide out of it.

In summary, we were extremely happy when our guy got well and took back over. The two farmers were great to work with and very understanding. I know they got tired of me calling the first couple of weeks trying to find my way to certain fields.

I did not recommend anything much different than I recommend over the telephone or in spot field visits on a daily basis. However, making the recommendations and going back to the same fields four weeks in a row provided an excellent refresher course. It helped reinforce some of the recommendations I use on a daily basis, but it also provided a better understanding of some of the things that can go wrong.

It also reinforced the fact that you cannot mess around killing barnyardgrass. You have to hit it hard before it comes up and often again as it emerges. Failure to get it under control by the three- to four-leaf stage often leads to an expensive herbicide bill and often a disappointing level of control.

The last thing I learned is rice scouting is hard work and carries with it a great deal of pressure. My hat is off to the folks who do it for a living and do it well.

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