EPA has extended the comment period until Nov. 14 on a proposed label change for sulfonylurea herbicides currently used on millions of U.S. crop acres. The label changes proposed by the agency could impact how and if you use any product containing the active ingredient, notes Richard Gupton, senior vice president of the Agricultural Retailers Association.

GOT A COARSE-SPRAY NOZZLE? Proposed EPA label change would require it for applying any herbicide containing sulfonylurea.

That would cover a long list of herbicides and premixes including Accent, Basis, Classic, Canopy, Finesse, Harmony Steadfast, Synchrony and many more. Using the most conservative models and endpoints to predict exposures of concern, EPA has determined that risks to non-target plants warrant additional label restrictions when products are applied either by ground or air, says Gupton.

Label restrictions under consideration
To protect against that predicted potential damage, EPA proposes that labels require:

• All applications of products containing a sulfonylurea must be made using equipment delivering an extremely coarse droplet size.

• All applications would be prohibited when site wind speeds exceed 10 miles per hour.

• When making aerial applications, maximum boom lengths, swath displacement and nozzle orientation must be defined and mandatory.

• In ground spraying, distance between the spray nozzle and the ground or crop canopy would be restricted to no more than 2 feet.

• Tankmixes with different mode-of-action and herbicides such as glyphosate would be prohibited if the extremely coarse droplet size is required as these applications generally require small droplet size to be efficacious.

To comply with the law, many weed control claims would need to be taken off product labels until new supporting data could be developed. Most SU herbicides are also applied in tank mixtures with different mode-of-action and herbicides such as glyphosate. 

The take-home message
While the agricultural industry generally supports for spray drift advisory language, placing specific restrictions on equipment types, configurations and operating parameters may discourage applicators from investing in newer technologies designed to better manage drift, contends Gupton. “The investment required to continue to apply sulfonylureas appears to have been overlooked.”

EPA requires that all performance claims on a label be supported by data. However, little if any performance data exists when products are applied in extremely coarse droplets. Requiring extremely coarse spray droplets may, in effect, remove some SU products from the marketplace.

Then there’s the conversion cost to ultra-coarse droplet nozzles. ARA suggests the cost could be in excess of $2 million for the commercial applicator industry of about 4,000 rigs. That’s putting the cost at $10 per nozzle x 50 nozzles, or $500 per applicator. That does not include farm-owned applicators.

EPA also proposes that labels instruct users to scout for resistant weeds before and after an application, and report any lack of performance. Labels would also be required to list confirmed resistant weeds and provide separate use-rate instructions for treating them. 

ARA asks that you take the time to submit your concerns and comments to the EPA. To add to the confusion, EPA has established a different Public Docket for each of the 22 sulfonylureas currently registered for use. The complete proposed interim decision may be found in any of the dockets. Comments applicable to any sulfonylurea may be submitted to any one of the dockets.

For more details on filing comments, click the link below to log in and send your message: votervoice.net/BroadcastLinks/Ifza7ubyM7b6GrvzQ9sSeQ.