From the Cotton Grower 2015 Annual
As the old saying goes, “Things are always bigger in Texas.” In 2015, that could also apply to growers’ battles with glyphosate-resistant weeds, including Palmer amaranth and waterhemp.
Early season rains slowed planting a bit, and left cotton fields with much-needed moisture to get the crop out of the ground once planting resumed. But the rains also brought an overwhelming flush of weeds to many parts of the state.
Growers who were able to apply preplant residual herbicides as scheduled were ahead of the game when it came to weed management through the season. But others who were weathered out of timely treatments had to do the best they could to try to clean up their fields, resorting to post-direct applications under a hood and hand weeding.
Growers who have been fighting glyphosate-resistant Palmer amaranth in other parts of the Cotton Belt could certainly sympathize, as their own challenges continued. A recent survey showed that more than 84 million acres of U.S. farmland (all geographies) are infested with glyphosate-resistant weeds. And that number continues to climb each year.
Little wonder that growers are looking for new alternatives for weed control.
In January, USDA deregulated the Bollgard II XtendFlex trait from Monsanto, which would allow for over-the-top applications of glyphosate, glufosinate and dicamba. Likewise, in July, USDA cleared the Enlist cotton trait from Dow AgroSciences for use of glyphosate and Enlist Duo – a new, low volatility formulation of 2,4-D – on the crop.
EPA approvals of the new dicamba and 2,4-D products for cotton are still pending and are anticipated before the 2016 season.
The fight against root knot nematodes in parts of the Cotton Belt gained new tools with the introduction of Velum Total, a new in-furrow nematicide/insecticide from Bayer CropScience.
Coupled with effective nematode-resistant cotton varieties from Deltapine, Stoneville and PhytoGen, growers now have more options for matching the level of protection needed on a field-by-field basis. One of those varieties – ST 4946GLB2 – was the top planted variety in the U.S. in 2015, according to the USDA Varieties Planted report.
Insect control issues also kept growers, especially in the Southeast and Mid-South, on guard in 2015.
Plant bugs were again ranked as the top insect pest in cotton, although stinkbugs and thrips added to the headache as well. Lower market prices also left some growers looking for more economical options for insect management.
Possible resistance issues continued to be a concern, especially regarding the effectiveness of some seed treatments on thrips. University and company research efforts are ongoing, looking for answers and solutions.
Regulatory issues also cloud the future for several effective insect management tools. EPA has proposed revoking certain tolerances for some products, including acephate and chlorpyrifos, although final decisions have not been announced. And, despite reams of research data affirming their safety, neonicotinoid products continue to be under fire as a cause of bee deaths.
The most surprising move of 2015, however, came in September, when the U.S. Ninth Circuit Court of Appeals vacated the EPA registration of sulfoxaflor – or Transform – stating that the agency erred by granting the registration without additional studies regarding potential impact on honeybees. Growers who have on-farm supplies of the product are allowed to use in 2016, but no new distribution will be permitted under the ruling.