CRB-Sponsored Citrus Showcase Seminar Latest Available Strategies for Managing ACP in Your Orchards

CRB-Sponsored Citrus Showcase Seminar

Latest Available Strategies for Managing ACP in Your Orchards

After the CCM Citrus Showcase lunch program, stick around and hear Beth Grafton-Cardwell, Ph.D., an Integrated Pest Management Specialist with the University of California, Riverside and the Director of the Lindcove Research and Extension Center deliver a talk about the work her team has been doing studying Asian citrus psyllid (ACP) management for the past several years in southern California. Nastaran Tofangsazi, Ph.D., a post-doctoral researcher at the University of California, Riverside, has been evaluating insecticides and conducting field trials to determine the residual impact of conventional and organic insecticides. This research is supported by a Citrus Research Board (CRB) grant and a U.S. Department of Agriculture (USDA) Technical Assistance for Specialty Crops (TASC) grant. In 2017, Grafton-Cardwell was awarded USDA Multi-Agency Coordination (MAC) Group funding to hire a team of four psyllid scouts to conduct year-round monitoring of 180 commercial citrus orchards in southern California. Their biweekly sampling is ongoing in the Ventura, San Bernardino, Riverside, Temecula, San Diego, Coachella and Imperial citrus growing regions. The orchards use various psyllid management practices, including broad spectrum, soft and organic insecticide strategies. The data the psyllid scouts are collecting is providing critical information about the impact these management strategies have on the psyllid populations and assisting Task Forces and Pest Control Districts in developing effective psyllid management programs. 

An important result of this research is that the psyllid is “all about the flush,” and so the heaviest psyllid populations are occurring in areas where trees are flushing continuously, such as Ventura, Riverside and San Bernardino, and lowest in the desert areas where the flush hardens off for long periods of time. Broad-spectrum, long-residual insecticides reduce psyllid densities the most, especially during the fall when conditions are most favorable for psyllids. ACP populations often start on the edges of groves, and so border treatments could be applied when psyllids begin to develop on these edges, making subsequent whole-orchard, area-wide treatments more effective. 

With the assistance of Sandy Olkowski, Ph.D., at the CRB, the psyllid collections also are providing information for the team to develop a rapid presence-absence method of ACP monitoring, sampling strategies to determine if psyllids are on the borders and treatment thresholds that could be utilized by Pest Control Advisors to assist growers with psyllid management. During the CRB’s Showcase workshop, Grafton-Cardwell will provide an overview of the psyllid management tactics that currently are being conducted around the state and the level of psyllid control being achieved. 

She also will discuss new tactics being developed by researchers that could be added to the grower repertoire to improve existing psyllid management programs. These include the work of Mamoudou Setamou, Ph.D., Texas A&M University-Kingsville, who is working with screened fencing along the edge of orchards, which functions as a barrier to psyllid movement into the orchard. Grafton- Cardwell further will report on the project proposed by Philippe Rolshausen, Ph.D., to study the production of “Citrus Undercover Production System” (CUPS) at the Lindcove Research and Extension Center. This project will enclose citrus in screening to protect it against psyllids and determine the cost of production and the level of productivity of the trees. Additionally, Grafton- Cardwell will provide an update on the research of Mark Hoddle, Ph.D., into the efficacy of biocontrol releases of Tamarixia in residential areas. 

1.0 hour of “Other” Continuing Education Units have been
approved by the California Department of Pesticide Regulation.