Pest control, water quality issues take center stage Water quality and pest control issues have been priorities for CAFA and recent developments point to more of the same in 2001.
On the pest control front, efforts are under way to assess whether Sections 18 labels are viable options for meadow vole and lepidopterous insect control. Growers can contribute by providing economic data and comparing losses in affected fields vs. fields that escaped damage.
For meadow voles, the clock is ticking on a Section 18 for zinc phosphide. The California Department of Food and Agriculture has sent data to the federal EPA to add alfalfa to an existing 24(c) label for zinc phosphide, but it won't be acted on until well after the current Section 18 expires on Jan. 19. According to Senior Biologist Nick Condos of the CDFA, letters from CAFA members were a big help in getting approval for the current Section 18.
Grower input is needed again to help determine if there's a need for another Section 18. Contact CAFA at P.0. Box 162, Davis, CA 95617-0162, or by e-mail; [email protected]
A pest control issue that recently surfaced started with a call from Fresno County Farm Advisor, Shannon Mueller. She referred CAFA to a grower who experienced heavy armyworm and alfalfa caterpillar pressure. CAFA is contacting UC farm advisors and entomologists to determine the scope and severity of the problem.
Another CAFA priority, water quality issues, recently made headlines when environmental groups mounted a challenge to the Central Valley Water Quality Control Board's waiver authority, proposing that growers seek permits for field runoff and pay for monitoring of water quality. As opponents point out, it's impractical to require a discharge permit for every farm and the cost of monitoring provisions would be a heavy burden.
Chlorpyrifos levels The environmental groups' actions are a reminder to follow stewardship practices to avoid regulatory action. For alfalfa, a key issue is minimizing levels of chlorpyrifos (Lorsban, Lock-On) that enter natural waterways, especially in the Delta Region. The Alfalfa Pesticide Task Force, a joint venture of CAFA and the California Alfalfa Workgroup, is meeting with regulatory agencies to develop practical, voluntary measures growers can use to reduce chlorpyrifos levels in surface water.
Yolo County Farm Advisor Rachael Long has issued several suggestions that bear repeating. They include:
- Minimize irrigation runoff from fields and know where water flows. If possible, develop tailwater return or neighbor-field recycling systems.
- If irrigation runoff can't be controlled and flows into a natural waterway and the Delta, consider using pyrethroids. Low water solubility makes them less likely to move off site.
- Whenever possible, avoid spraying weak areas of a field with chlorpyrifos. Reducing the amount of material deposited on the soil reduces chances of off site movement.
- In fall, consider overseeding weak stands with berseem clover, oats or grasses. Weevils won't feed on the overseeded crops and they'll replace lost production due to weevils, negating the need to spray.