On Nov. 15, 2018, the California Department of Pesticide Regulation (DPR) announced additional restrictions on the use of chlorpyrifos (e.g., Lorsban) within the state of California. These restrictions are “recommendations,” or interim, until DPR completes the steps required under the recent listing of chlorpyrifos as a Toxic Air Contaminant.
Since it is a recommendation, its implementation is being left to the County Agricultural Commissioners (CAC) to determine.
The Almond Board’s observations of these restrictions are that they will make it all but impossible for almond growers to use chlorpyrifos. The major changes within the restrictions include:
- Chlorpyrifos may only be used for the critical pests of leaf-footed plant bug and stink bugs in almonds. This means that to obtain a permit to use chlorpyrifos, growers need a Pest Control Advisor to certify to the CAC that the pest is present.
- The Notice of Intent to spray needs to be submitted to the CAC at least 48 hours before the planned spraying.
- Chlorpyrifos may only be applied to a 40-acre block within a half mile of any other treatments within each 24-hour period.
- There must be a quarter of a mile, or 1320-ft, buffer zone around any application, in which no human activity may take place expect for mixing and loading of chlorpyrifos and its application for air blast applications.
- Can get written permission from adjacent property owners to extend into it, and buffers can cross roads.
- There must be a 150-ft set back to any sensitive site, including homes, yards, outdoor recreational spaces, daycare centers, schools, sidewalks, etc. This is less than the interim regulations put in place last fall that required a 350-ft buffer for typical rates of chlorpyrifos used in almonds.
- Aerial applications are not allowed.
While DPR acknowledges that there are no good alternatives for chlorpyrifos for leaf-footed plant bug and the stink bugs, the permit conditions are not compatible with the way those pests need to be treated. This is especially the case with leaf-footed plant bug, which requires immediate treatment when it shows up in the orchard and/or when damage is noticed. The new restrictions — the time it will take to ensure the buffer zone can be met, to obtain a permit, the limitation of 40 acres in a day — will all likely mean most almond growers will no longer be able to use chlorpyrifos.
DPR did not reach out for feedback on the implications of the recommended mitigation measures prior to issuing. The Almond Board, in cooperation with the Almond Alliance, will continue communications with the EPA and DPR to provide background on how almonds use chlorpyrifos — and express concerns with the data used and lack of process for making these mitigation decisions.
The continued regulatory uncertainty around the availability of chlorpyrifos and other pest management tools demonstrates the importance of Almond Board-funded research into integrated pest management. This research typically seeks to better comprehend the pest’s biology to develop more optimal monitoring tools, understand vulnerable times for control, and evaluate both chemical and cultural or other non-chemical tools. Regarding leaf-footed bug, the Almond Board has been funding research on better tools for monitoring and control, its sporadic nature has hampered rapid progress. ABC is also conducting research on the brown marmorated stink bug, an invasive stink bug, that has recently shown up in orchards.
