Stakeholder development of agricultural management practices in orchards to reduce pesticides in surface water following dormant applications in Winter

The Organophosphate Pesticide Focus Group is a stakeholder working group of the Sacramento River Watershed Program (SRWP) that was formed to address the development of a TMDL for diazinon in the Sacramento River in northern California. The group's primary objective is to develop a water quality, management strategy to reduce diazinon runoff in the watershed following dormant (winter-time) orchard sprays to fruit and nut trees in northern California. The water quality management strategy is largely dependent on the activities of the Ag Implementation Group, which was organized to develop a strategy and a set of self-directed ("voluntary") Agricultural Management Practices (AMPs) that when implemented, will significantly decrease the negative impact of pesticide use on the natural resources of the Sacramento River Watershed. The practices being evaluated have been grouped into three categories: 1. On-Site Practices for Runoff Reduction-Includes cover crops, vegetative filter strips, grassed waterways, water and sediment control basins, berms at low ends of fields. etc. 2. Selection of Pest Management Strategic-Includes alternate year dormant applications, no dormant sprays/in-season as needed, conventional non-OP dormant sprays, bloom-time sprays, pheromone mating disruption, and other pest management strategies. Decisions are based upon field scouting and the use of pest management models. 3. Application Methods-When and where applications are required, includes use of setback/buffer zones, drift mitigation practices, sprayer calibration, nozzle selection, electronic sensors, new equipment technology, etc. A broad menu of management practices has been incorporated into the strategy from which growers can voluntarily select, choosing the combination of practices that best suit their site(s), operations, and needs.