With rice planting near, here are two general themes going into the weed control season.
The first one is that in most fields, weeds can be controlled with herbicide costs of $25 to 45 per acre.
A program in that price range that fits a lot of fields is Command applied at planting followed by a propanil product plus Permit applied preflood.
Another program used a lot last year was Command applied pre, followed by Duet plus a reduced rate of Facet applied preflood.
Depending on the situation, several other herbicides — such as Aim, Ricestar and Clincher — can be used in some of the postemergence applications.
In most cases the goal should be to achieve preflood weed control with two trips across the field. If applications are timely and work as they should, weed control should not require the top-end rates for the herbicides chosen.
The second theme is the influence of moisture in making treatments work properly. I hope everyone knows now that a rain or flush is necessary to make the Command work — the key to staying in the price range listed above.
If it doesn't rain and you have applied herbicide, you simply have to flush. If we are in a dry period and you have not applied Command, you have the option to attempt to time it in front of a rain or to time it to when you have to flush to get a stand.
The moisture thing goes well beyond making the Command work. It is just as important as proper timing in making the postemergence treatment work.
Whenever possible, apply the postemergence treatments after rain or flushes. The soil does not have to be sloppy muddy, but actively growing weeds and a soil surface wet enough to create high humidity in the microclimate where the weed is living make herbicides much more active.
If you make a mistake by choosing the wrong herbicide or by failing to give the herbicides the best chance of working properly, then salvage herbicides enter the picture and herbicide costs can easily go to $75 per acre and above.
Due to the hard times and the new postemergence tank-mix label for Command, growers are talking about just throwing one shot of Command with a big load of propanil and calling it a preflood program. That can be a good herbicide treatment, but in few fields will it be a good program.
Getting by cheap always sounds good up front. When the weeds grow out the top after flooding, panic sets in and you throw $50 per acre at them and often that doesn't work.
Keep a commonsense approach to your program and plan on a two-trip approach preflood. Perhaps you will get lucky and one shot does it, but you cannot count on it.
Staying within $25 to 45 per acre comes from using the high-percentage proven treatments and avoiding a third application for grass control.
Ford Baldwin, Practical Weed Consultants. e-mail: [email protected].