We start monitoring Lambda-cyhalothrin (Warrior, Lambda-cy, Silencer, etc.) in the water column plus sediment sampling this year. The sampling takes place at the drain sites we use for thiobencarb monitoring. This will be our first experience with compliance to the Total Maximum Daily Load (TMDL) requirements. The TMDL is a forever monitoring program and we anticipate positive results leading to future modifications. We have never had an issue with our long history monitoring the pyrethroid insecticides. However, we have no ability to correlate the past results with the newer and much lower analytical methods.
What does this mean to growers and applicators in rice country?
Our industry does a great job applying pyrethroids for early season pest control. The majority of applications are boarder treatments to target the area of the field early season insect pests thrive. We need to be aware of all field boundaries when making boarder treatments. Fields next to a drain can adjust the application to cover more of the field rather than the edge of the boarder.
What is a TMDL?
Total Maximum Daily Load is a regulatory term from the U.S. Clean Water Act. The TMDL defines a plan for restoring impaired waters by identifying the maximum amount of “pollutant” the water body receives while still meeting water quality standards.
What are 303(d) listed water bodies?
Under the U.S. Clean Water Act, this is the list of impaired or threatened waters (streams, rivers, segments, lakes, etc.) that identify a pollutant as causing the impairment. The list is updated every two year. The pyrethroid TMDL lists 14 waterbodies: nine from municipal storm water and five from agricultural discharge in the Central Valley.
List of pyrethroid insecticides
Pyrethroid is the class of insecticide that includes the active ingredients: Bifenthrin, Cyfluthrin, Cypermethrin, Esfenvalerate, Lambda-cyhalothrin and Permethrin. The regulation is per active ingredient with no relation to the labeled name. We have approval to specifically monitor Lambda-cyhalothrin based on usage data to rice fields.
For more information, contact the CRC’s Industry Affairs Manager Roberta Firoved at firstname.lastname@example.org or (916) 206-5039.