1a. Objectives (from AD-416)
Determine if new plantings of citrus can be protected from citrus greening disease using insecticides.
1b. Approach (from AD-416)
Establish new, disease-free plantings of citrus in the vicinty of Immokalee and test various insecticide programs for protecting the trees from infection.
3. Progress Report
This project is related to Objective 3c: Investigate basic biology and ecology of the Asian citrus psyllid and its natural enemies in Florida citrus. A study on psyllid control was conducted to evaluate three insecticides (cyazapyr, Admire Pro, and Platinum) applied to young trees. Cyazapyr at a medium and high rate provided up to 10 months of psyllid control. Another study is designed to continue for 3 years with rotations of cyazpyr at a low and medium rate with Platinum and Admire Pro every three months. The objective is to assess the ability of these treatments to delay or prevent the onset of Huanglongbing (HLB) in an area of high incidence. Initial treatments were made 29th of July on newly planted Hamlin trees and evaluations conducted the 2nd and 22nd of September with no psyllids being observed although all treatments have been 100 percent effective in controlling leafminer. Applications were repeated on the 24th of January and 25th of April and evaluations on 13th of April and 18th of May by removing ten shoots per plot and counting nymphs under a stereo microscope. Untreated shoots were highly infested, but no nymphs were observed on shoots from treated trees except on the last sample date when a mean of 2.4 nymphs per shoot was seen with the rotation that began with Admire Pro and employed the low rate of cyazapyr, although this was not statistically different from the other three insecticide treatments. Leaf samples are being analyzed for residues of all insecticides. The general consensus is that insecticides remain a critical tool for psyllid control in preventing the spread of huanglongbing (citrus greening disease). Progress was monitored through direct involvement in lab and field activities, research meetings, and discussions with collaborators at U.S. Horticultural Research Laboratory (USHRL) and Animal and Plant Health Inspection Service - Plant Protection Quarantine (APHIS-PPQ), telephone calls and email communications.