As Mid-South cotton acres reached the early to mid-bloom growth stage in mid-July, growers were reminded they should not be surprised when they started seeing high plant bug populations.
At a July 11 Dow AgroSciences field day, market development specialist Dr. Drew Ellis reported that his regional reps had grower clients in Arkansas and northeast Louisiana who had reached the peak of their plant bug control efforts.
“Those two areas of Arkansas and Louisiana are the southern portion of our cotton business region." In areas where corn was drying down, farmers watched for plant bug populations migrating into blooming cotton, said Ellis.
Ellis and other DowAgroSciences and PhytoGen scientists showcased some of their cotton, soybean and corn technologies, like Transform WG insecticide and Elevore, a new burndown herbicide, on one of their regionally-managed Innovation Field Plots outside of Halls, Tenn.
Growers know when heat units crank up and cotton begins putting on fruit, plant bug management is both inevitable and necessary to protect young cotton squares and the subsequent crop’s yield potential.
Transform lost its registration for cotton during the 2015-16 season, but was granted a Section18 for all Mid-South states, as well as Arizona and Texas for 2017.
“Transform is the most effective product on the market for plant bug control — and for protecting yields. We had 25 consultants conduct large field trials with the labeled rate of Transform compared to a non-Transform field at the commercial standard rate and we saw nearly 40 pounds more lint on average with the Transform program over 80 percent of the time. That’s an excellent returned value to the farmer,” said Ellis.
Through its translaminar activity, Transform’s chemistry gets into the plant’s system through its leaves to fight off adult plant bugs, helping to ensure good square retention and fruit load. Where eggs have already been laid, it helps control subsequent post-hatches.
Ellis knows tarnished plant bug damage is where growers lose profit, so he advises control efforts should be targeted toward them.
“Pigweed and other weeds like winter annuals and curly dock act like a ‘green bridge’ to cotton, so if weeds aren’t controlled, they become easy access hosts for insects,” said Ellis.
When pyrethroids are used to control tarnished plant bug populations, the risk of insecticide “flare” is increased. Flare occurs when an applied product reduces the beneficial insect population which helps to provide natural plant bug control. Bee groups regularly stress they want growers to use the safest products available on their crops.
“We need to preserve as many beneficial insects as possible, and in that regard, Transform is one of the safest products available to cotton producers, and it can also be tank mixed with other products,” said Ellis.
Around 2000, marestail, or horseweed, was the first weed growing in an agronomic field to develop resistance. Discovered in Delaware, it quickly moved across the Midwest and into the row crop areas of the Mid-South.
“It’s not only resistant to glyphosate, it’s resistant to ALS and triazine chemistries, so if you can’t control it early in a preplant burndown situation, there’s almost nothing ‘in crop’ you can use to gain control,” said Dr. Jeff Ellis, field scientist for Arkansas and Louisiana, Dow AgroSciences.
Marestail is a very adaptive weed, germinating in the winter, spring, and summer. It became prevalent when farmers were moving from conventional tillage to conservation tillage or no-till.
The benefits of a good burndown at the start of the growing season are well-documented and will pay dividends as the crop moves forward through its growing stages.
“We’re excited about Elevore’s potential (pending full regulatory approval) to give growers a new labeled-use tool to target marestail up to 8 inches tall,” said Lindsey Hecht, soybeans herbicides product manager, Dow AgroSciences, who also mentioned regulatory approval is expected in the fall of this year for use in the 2018 burndown season.
Hecht and Ellis have conducted field trials with Elevore in the Mid-South and the Midwest for the last several years. It has a low 1-ounce use rate which is important when mixing it with other products. Comprised of a new active ingredient, Arylex Active, Elevore is absorbed through a plants leaves, roots and shoot, then translocates for control of ALS and glyphosate-resistant weed species.
“This product will offer growers more flexibility and can be applied in both the fall and spring, and is approved for ground and aerial application,” said Hecht.
The initial label will be for corn, cotton and soybeans, with a 14-day preplant application on soybeans and corn, and 30-day preplant application on cotton.