WALNUT PEST MANAGEMENT ALLIANCE 2003 - YEAR 5 UPDATE

The walnut PMA work plan continues with the broad based implementation project designed to encourage adoption of reduced-risk pest management programs in walnuts statewide. The focus of this project is to continue current efforts to demonstrate economical reduced-risk management strategies on walnuts and to improve communication and cooperation among the different groups involved. The PMA project has evolved into a broader program than originally envisioned with individual researchers working closely with the PMA in the area of codling moth and blight. This research feeds directly into the PMA project, allowing the PMA project to better focus on testing and demonstration that are near term. Several factors have increased the prospects for development of reduced risk practices for codling moth, which is the primary target for broad spectrum insecticides in walnuts. These factors include the documentation of resistance to the most commonly used insecticides and the development of newer pheromone application technologies such as sprayable pheromone and puffers. This coupled with the development of new, more selective insecticides that can help provide control without disruption of naturally occurring biological control. The codling moth PMA project in 2003 again demonstrated pheromone mating disruption at the five sites with the using two different rates of Suterra CM-F in the sprayable formulation. Since sprayable pheromone is more practical for walnut growers to apply, there is a higher probability that growers will incorporate it into their existing codling moth control programs. In addition, the project expanded to include 18 grower implementation sites throughout the walnut growing region. The implementation sites were managed by the grower and PCA using protocols written by the walnut PMA. The PMA sites used the newest technology in a lure for monitoring with traps that contains a kairomone instead of a pheromone, and catches both males and females. The PMA has continued to test Xanthocast, the walnut blight model, as well as helping growers learn to use the model. A satellite project using reduced risk materials for walnut husk fly management was conducted in as well. The PMA will continue to develop management techniques from research funded by the Walnut Marketing Board, using UC IPM monitoring programs refined by the walnut PMA, and outreach programs that will result in increased adoption of a reduced-risk walnut program to decrease the use of pesticides in walnuts.