Sweet corn hybrid tolerance to Accent, Callisto, Impact, and Laudis was summarized in an earlier Wisconsin Crop Manager article. This article reviews updates on Accent, Option, Poast Protected hybrids, and acetochlor. 

 

Accent: DuPont has announced an updated list of processing hybrids on which Accent use is recommended. The new hybrids added to the list are underlined below. Interestingly, we have also tested the tolerance of four of these hybrids (Chase, Dynamo, Eliminator, Suregold) and two iso-line hybrids (Basin R and 710 R) in our multi-state trials and found them be to more sensitive than the more tolerant hybrids. We have also tested Bliss, Challenger, Enterprise, HM 2390, Legacy, Rocker, Rustler, and Sheba and rated these hybrids as tolerant.

Processing sweet corn hybrids approved for Accent use by DuPont.

ABCO Var. #610	GG 8	GH 9589	Prelude
Basin	GG 43	GH 9597	Reward
Bliss	GG 63	GSS 8357	Rocker
Bonus	GG 202	GSS 8388	Rustler
Challenger	GG 214	GSS 9299	Sheba
Chase	GG 228	Harvest Gold	Sockeye
Crisp’N Sweet 710	GG 236	HMX 2390	Spirit
Crisp’N Sweet 710A	GG 255	Jet	Sprint
DMC 20-04	GG 435	Kokanee	Suregold
DMC 20-35	GG 446	Lancaster	Wht 2801
Dynamo	GG 455	Legacy	XP 08705808
Eliminator	GH 0937	Lumina	781 Ultra
Empire	GH 2547	Obsession
Enterprise	GH 2690	Overland
Excalibur	GH 6462	Passion

 

In terms of comparing Option to Accent for postemergence grass control in sweet corn, Accent is labeled to control wild proso millet up to 4 inches tall and should provide slightly greater control than Option. Sweet corn hybrids also tend to have greater tolerance to Accent than Option. We tested 149 hybrids for tolerance to 2x rates of Accent and Option in 12 trials across the U.S. Although the level of injury varied among the hybrids and locations, the overall average injury was 7.9% with Accent and 12.2% with Option. This suggests that if conditions are stressful or if the hybrid tends to be more sensitive, the potential for injury is greater with Option than Accent. Laudis and Impact are also options for controlling wild proso millet postemergence in sweet corn. Laudis is labeled to control 4-inch tall millet alone and 5-inch tall millet when tank mixed with atrazine. Impact at 0.75 oz/a is labeled to control 3-inch tall wild proso millet.

 

Poast and Poast Plus: In previous years, only Poast was labeled for use on the Poast Protected sweet corn. However, the Poast Plus label now includes Poast Protected sweet corn hybrids (Rogers has six Poast Protected sweet corn hybrids). Both herbicide formulations have the same active ingredient (sethoxydim). Poast Plus has a lower sethoxydim concentration than Poast so the use rates of Poast Plus are higher than Poast. Poast Plus rates are 0.75 pt/a for wild proso millet and 1.5 pt/a for most other annual grasses.  Poast Plus also has some adjuvant included in the formulation, but crop oil should still be added in most situations. I’ve been asked if Poast Protected sweet corn is equally tolerant to both formulations and the answer is yes. One side note is that the Poast Protected hybrids are not genetically engineered. This form of resistance was selected from corn tissue culture. These plants only have corn genes; foreign genes from bacteria or other plants were not introduced to create the resistance.

 

Acetochlor: Most acetochlor products (Harness, Surpass, etc. and the atrazine premixtures of Harness Xtra, Keystone LA, etc.) have added sweet corn to their labels. Acetochlor controls many annual grasses and some broadleaf weeds preemergence. Although most people are familiar with these products, a few comments are in order.

 

Acetochlor use restrictions: 

 

 

The acetochlor products that you have purchased may or may not have sweet corn listed on the label of the container. If the label does not list sweet corn as an approved use, it cannot be used on sweet corn even though newer labels may have this updated use. At the time of writing this article, the Degree and Harness Xtra labels posted on CDMS include sweet corn, but new Harness and Degree Xtra labels with sweet corn have not been posted. In the case of Dow products like Surpass or Keystone, supplemental labels are posted on CDMS, which allows their use on sweet corn if you have possession of the supplemental label.