Stone fruit pesticide reduction success in California

Background

Many people enjoy the time of year when they go to the grocery store to happily find that peaches are in season. The juicy, crisp taste of a peach on a hot day is hard to beat. A project funded by EPA is promoting sustainable ways to grow these delicious peaches.

Peaches belong to a class of fruit known as stone fruit, which also include nectarines and plums. The production of stone fruits typically involves the use of some pesticides targeted for reduction by the Food Quality Protection Act (FQPA) implemented by the California Department of Pesticide Regulation.

Why Reduce Pesticides?

The reduction of pesticides can help reduce negative impacts to human health and the environment. Pesticides pose a health risk to farm workers and farm families. The unintentional movement of pesticides through drift and soil erosion and potential contamination to water sources. Economically, an effective switch from pesticides to a more integrated program can help farmers increase profit margins.

EPA funded a project with the California Department of Pesticide Regulations to study alternate means of pest management in the production of stone fruits. The goal of the project was to reduce the use of five FQPA-targeted pesticides, phosmet, chlorpyrifos, carbaryl, methidathian and diazinon, by 20% in the Parlier area of California. These five pesticides are typically used on stone fruit to control the following pests; Oriental fruit moth (OFM), peach twig borer (PTB), San Jose scale (SJS), Omniverous leafroller (OLR), Western flower thrips, katydid and web spinning mites.

Results

The project demonstrated the benefits of transitioning to less harmful pesticides and reducing the amount of pesticides used. The results also showed that pesticide reductions can have economic benefits for growers.

Overall, 17,000 acres of stone fruit were impacted by the project and showed a reduced use and cost savings of almost 30% on average, with no negative effect on insect pest control. Specifically, this was due to three pest management changes: the use of target-sensing sprayers, pheromone-mating disruption, and the use of oil in the dormant seasons.

• Target-sensing sprayers, in this case SmartSpray®, use ultrasonic sensors to directly spray the trees. Using the target-sensing sprayers resulted in a 47% savings in spray material as compared to conventional practices.
  
  
• The San Jose scale, a prominent stone fruit pest, is typically managed during the dormant season with oil and insecticide. This project demonstrated that the oil alone will control low to moderate San Jose scale levels and mite eggs and also protect beneficial insects. Additionally, elimination or reduction in insecticide use results in a cost savings to the grower.
  
  
• Pheromone-mating disruption involves introducing synthetic pheromones into crops, thereby preventing undesirable insects from mating. This, along with the use of beneficial insects and plants which provide habitat for the beneficial insects is an environmentally friendly way of controlling pests.

Future Potential

While the project was very successful in impacting 17,000 acres of stone fruit, there is great potential for the increased use of these technologies. Six growers and five pest control advisors actively participated in this project and over 2,000 growers attended field days and/or demonstration events related to this project. Estimates show that the beneficial practices demonstrated could potentially impact approximately 200,000 acres. This means 200,000 acres of stone fruit grown with significantly less pesticides, reducing the risk to human health and our environment.

Source: U.S. Environmental Protection Agency, Pacific Southwest, Region 9