Time for ACP Dormant Season Sprays

Tacy CalliesHLB Management, Tip of the Week

Asian citrus psyllid

By Lauren Diepenbrock

Pest management is an ongoing effort in Florida citrus. Taking advantage of pest life cycles, whether they are tied to the season or plant phenology, can make management efforts have greater impacts on pest populations.

For many citrus growers, managing the impacts of Asian citrus psyllid (ACP), the vector of huanglongbing (HLB), is part of the annual management plan. As we enter the cooler winter months, it is time to implement dormant season sprays for ACP. With little to no flush available for offspring production, dormant season sprays take advantage of a largely uniform population of psyllids at this time of year. By targeting the adult population, growers can decrease the mating population before spring flush, reducing the capacity of the population to increase rapidly.

As a stand-alone method, Jawwad Qureshi and Phil Stansly (2007) showed that dormant sprays both reduced the adult population of ACP while having negligible impacts on key predators of both ACP and other pests of Florida citrus.

Dormant sprays can be incorporated into a spray program that takes advantage of ACP’s reliance on tree phenology for development. A budbreak phenology model can then be used to target adults at the beginning of each major flush cycle to reduce the reproductive adult population, followed by additional sprays targeted to periods of heavy flush to kill nymphs as they are developing to keep the ACP population down. Research by Gene Albrigo and Lukasz Stelinski has shown this management plan to reduce ACP more than monthly sprays.

Insect pest management has always been a moving target in Florida citrus. Dormant sprays are a proven method used across multiple crops around the world to reduce pest pressure prior to spring initiation of plant growth and pest population growth. As such, these sprays are an integral part of an integrated pest management program.

Learn more about ACP control here.

Lauren Diepenbrock is an assistant professor at the University of Florida Institute of Food and Agricultural Sciences Citrus Research and Education Center in Lake Alfred.