By Chris Boisseranc, Southwest Ag Consulting, Redlands
Reprinted with Permission from California Farm Bureau Federation
The Asian citrus psyllid is a pest that carries the bacteria for huanglongbing, or HLB, also known as citrus greening. HLB will kill the trees, but it takes three to five years, starting with the root system, then the upper canopy.
HLB is a vector-based disease spread by the psyllid. Typically, the psyllid will start in one area of the grove, move into the trees and feed on an infected tree, then move to an uninfected tree, spreading the disease.
Most of Southern California is under federal quarantine for HLB. Once a federal quarantine is in place, if an infected tree is found, a 5-mile quarantine is placed over the entire area. These quarantines make it difficult for growers to transport their fruit to market.
In Southern California, growers are doing regionwide treatments to maintain psyllid levels as low as possible and keep the HLB at bay.
In coordination with pest districts, the applications are done in a tight timing pattern so that growers can really knock down the psyllid. The goal is treat everything within a two-week window, using a material that’s appropriate not only for the psyllid but also mealybug, red scale and citrus mites. Doing combined applications for several pests is budget-friendly because of the reduction in applications.
Organic and conventional materials are available. Some chemicals kill all the pests—ACP, mealybug, red scale and citrus mites. These materials are a little more expensive. For organic growers, there is an oil that suffocates most of these pests all at the same time, and it does a good job.
Several chemicals are available so that growers can rotate and prevent resistance from building. Really good control has been seen with these products, particularly with tighter application timings in the regional districts during the 14-day window.