March 25, 2009

3 Min Read

Rice planting is near and it is time to figure out how we are going to do things from a weed control standpoint. I do not know what the percent of the acreage that will be planted to Clearfield rice, but it would seem to equate to whatever the seed supply was.

As a weed scientist I am concerned that planting over half of the acreage to Clearfield is taking us down a road we should not be going. However, growers have made that choice, so we will do our best to make it work and hopefully sustain it.

The seed companies and BASF have stepped up their educational efforts on stewardship. While I am all for it, the key to stewardship is a systematic rotation between Clearfield rice, alternate crops and conventional rice varieties. This can not happen when Clearfield acres get too high.

The Clearfield acres this year are going to present an interesting scenario for both farmers and the herbicide companies. I do not believe the Clearfield system is sustainable using only Newpath and Beyond for weed control.

One sample of barnyardgrass tested positive for Newpath and the other ALS inhibiting herbicides at the University of Arkansas this winter. With the frustrations a lot of consultants had controlling barnyardgrass in Clearfield rice last season, I would bet there are other ALS-resistant barnyardgrass populations out there.

Some growers may to just try to make the Newpath and Beyond system control all of their grasses and red rice. Two applications of 4 ounces of Newpath will cost around $25 to $30 per acre.

Many of the Newpath applications are now going out at rates higher than that. Two applications averaging 5 ounces per acre will cost around $30 to $35 per acre.

If a Beyond application is needed, add roughly another $20. Some broadleaf weed control is needed in most Clearfield programs, so I will estimate $10 per acre, although it could be more.

Therefore, in a Clearfield program using two applications of Newpath, one of Beyond, and some broadleaf control, you could budget $40 to $60 per acre in herbicide costs, which is good.

The problem is this program often is not controlling barnyardgrass, and it is weak on sprangletop. I recommend that Command be used on essentially every acre of Clearfield rice to take as much barnyardgrass out of the picture as possible and to control the sprangletop. I think Command gives us the best chance to keep ALS-resistant barnyardgrass from killing the Clearfield technology in three years or less.

The Command application adds another $10 to $15 per acre in herbicide costs. Hopefully this will do it, but a lot of Facet is used in the Clearfield programs and that can add another $10 to $25 per acre, depending upon the rate and how it is used.

If you do not use Command, perhaps the Facet will suffice — that is if you do not have Facet-resistant barnyardgrass.

Also, if you leave the Command off and sprangletop comes through, a Ricestar HT application will be required.

By now you are probably saying, “Doc, I am about to burn this cotton-picking article!” Unfortunately, programs like I am describing were all too common in Clearfield rice last year. Hopefully this year will show us last year was a fluke. If not, however, I am concerned that in some fields it will take the Newpath and Beyond budget just to control the red rice and then about as much money as you have been spending in conventional rice to control the grass and broadleaf weeds.

Again, I hope I am wrong because if I’m not wrong that means $100 per acre herbicide programs. Farmers are going to have a hard time enjoying that.

In addition, the costs of many of the herbicides have increased significantly. While these costs may seem ok on an individual herbicide, it does not take into account how many herbicides are required in a given field. Every company wants on as many acres as it can. There is only so much money to go around, so this could get interesting.

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