Play a new herbicide card in corn weed control game

Recent University of Georgia crop enterprise estimates suggest field corn has the potential to be one of the most profitable crops grown in this region in 2010. When I wrote this article in January, March to December corn contracts were selling between $4.21 to $4.48 per bushel. I hope it stays that way. Having corn in a rotation where atrazine and other modes of action can be used is a great way to combat glyphosate and ALS resistance!

Key Points

• Field corn offers a profitable option for Southern growers.

• The crop also offers options for managing weed resistance.

• Four new corn herbicides expand rotation options.


According to recent USDA estimates, about 68% of the U.S. corn crop in 2009 was planted using herbicide-resistant technologies. Unfortunately, the popularity of herbicide-resistant cropping systems has stalled the development of new active ingredients. Thus, the list of newer products available for use in corn is somewhat limited. Here is a look at a few “new” products for 2010.

Accent Q

Accent Q is a new formulation of Accent from DuPont that includes a crop safener known as isoxadifen. A safener is a substance that protects plants from herbicide damage. Thus, isoxadifen enhances the metabolism of the herbicide, which reduces the potential for crop injury problems associated with environmental extremes and other causes. Isoxadifen is also used as a safener in corn herbicides such as Laudis, Option and Status. If you’re wondering if the safener really works, check out the adjacent photos for some visual proof. The normal use rate for Accent Q 54.5WDG is 0.9 ounce per acre.

Steadfast Q

Steadfast Q, also from DuPont, is a mixture of Accent and Resolve. Additionally, Steadfast Q contains the crop safener isoxadifen. One benefit of this herbicide is that it may provide slightly more residual control of grass weeds than Accent alone. Results of my 2009 field tests suggest that post-emergence annual grass control between Accent and Steadfast Q was equivalent. Steadfast Q may be priced more competitively than Accent. The normal use rate for Steadfast Q 37.7WDG is 1.5 ounces per acre.

Nic-It

Nic-It, marketed by Cheminova, is the first generic formulation of Accent. One big difference between Nic-It and Accent is that Nic-It is sold in a liquid formulation. Field trials conducted in 2009 showed no major difference in performance between Nic-It and Accent. The normal use rate for Nic-It 2SC is 2 ounces per acre.

Sharpen

Sharpen, one of BASF’s first Kixor technology herbicides, will be marketed in the field corn burndown and preemergence arenas (also soybeans). Sharpen contains the new active ingredient saflufenacil. Generally, Sharpen is considered to be a broadleaf herbicide. It is a PPO-inhibiting herbicide similar to other popular products such as Reflex and Valor. As mentioned before, I have some serious concerns about the current overuse of PPO herbicides in the South! Growers with lighter soil types may want to be cautious with this one. The normal rate of Sharpen 2.85SC is 2 ounces per acre.

It is easy to get caught up in the hype and hoopla surrounding the launch of any “new” herbicide. However, I always think it’s a good idea to try new products on a limited basis until you get a feel for how they work on your farm.

As always, good weed hunting!

Prostko is an Extension weed scientist for the University of Georgia.

03104241A.tif

WITH SAFENER: The safener isoxadifen protects the corn plant while the herbicide — in this case, Accent Q — kills the weeds.

03104241B.tif

WITHOUT SAFENER: Without the safener isoxadifen, Accent sometimes causes crop injury when sprayed in corn. The new formulation, Accent Q, includes isoxadifen.

This article published in the March, 2010 edition of SOUTHERN FARMER.

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