WSDA to revamp Eastern Washington herbicide rules

The Washington State Department of Agriculture plans to lay out in the fall new ground rules for spaying certain herbicides in Eastern Washington.

The rules will simplify when and how the herbicides can be used, said Joel Kangiser, policy assistant for the WSDA Pesticide Management Division.

“The rules are badly in need of updating,” he said. “They are very complex and confusing.”

WSDA limits when and where restricted-use herbicides can be sprayed to prevent the inadvertent killing of neighboring sensitive crops, particularly grapes. The regulations are in addition to labeling directions and apply only east of the Cascades, which has 96 percent of the state’s cropland.

Some rules haven’t been substantially revised in more than 20 years, according to WSDA. Over time, a patchwork of regulations have evolved, with requirements varying in 50 different areas. Updated rules that could apply regionwide would eliminate confusion and recognize advancements in technology, according to WSDA.

WSDA, farm groups and Washington State University have been meeting on subjects such as maximum wind speeds and the size of droplets to prevent drift. WSDA plans to present a formal proposal for public comment in the fall.

The 14-member work group agreed to propose prohibiting spraying when winds are above 15 mph. Currently, there is no statewide wind speed limit, though some areas have limits as low as 7 mph.

Kangiser said wind speed limits can be raised without endangering crops or weakening WSDA’s authority to fine applicators for drift incidents in light winds.

Wind speeds are irrelevant without taking into account other factors such as wind direction, heat and temperature inversions, he said.

The main reason to have any wind speed limit is public perception, he said.

“We get calls a few times a year from people who see an operation in the wind,” Kangiser said. “It may not be a problem, but (a wind speed limit) is a good stewardship thing and keeps from raising public concerns.”

WSDA also plans to revamp rules for nozzle and pressure settings. The settings determine the size of droplets to guard against drift.

The new rules likely will be based on standards set by the American Society of Agricultural and Biological Engineers to obtain medium, coarse or very coarse droplets.

The existing rules emphasis the size of nozzle openings, but because of changing technology the regulations can actually put crops at more risk, according to WSDA.

Kangiser said the work group has been unable to agree on regionwide hours for spraying or the weeks when herbicides with ester formulations will be banned. Differing topology and weather patterns made reaching a consensus on regionwide rules for those issues difficult, he said.

Ester is a class of chemical compounds prone to vaporizing in the heat and blowing to other fields. Such herbicides are prohibited in some places during warmer months.