1a. Objectives (from AD-416):
Identify optimal blends and application methods for semiochemical-based products to control citrus leafminer and citrus canker disease.
1b. Approach (from AD-416):
Replicated, multi-locational field trials in commercial citrus groves will identify the optimal mating disruption formulations and best application rate, coverage pattern and frequency for control of citrus leafminer.
3. Progress Report:
This project is related to inhouse project objective 1: Develop semiochemical-based control methods for citrus pests, particularly Asian citrus psyllid (ACP). A postdoctoral scientist was hired in September 2011. During spring 2012, field trials were established in St. Lucie County, 2 grower validation trials in St. Lucie and Okeechobee counties were completed and 2 validation trials in Charlotte and DeSoto counties were monitored in collaboration with univeristy and private industry collaborators, a custom applicator, grove managers, owners, and crop consultants addressing timing, coverage, formulation, longevity, and efficacy of mating disruption under various crop phenologies. A split-plot design was established to test the value of SPLAT CLM application when citrus leafminer populations are low during winter months. A February application had no effect on trap catch disruption after the second (spring) application. The second application significantly reduced trap catch for at least 4 weeks. A trial was established April 2012 to compare the current SPLAT CLM pheromone formulation (an off-ratio blend consisting of the major triene pheromone component) with a formulation that incorporates the natural 3:1 triene:diene blend of two pheromone components. This trial will focus on evaluation of longevity of mating disruption and the ability of the formulations to affect mating disruption across treatment gaps (skipped rows) of varying width. A validation trial was conducted in 100 acres of grapefruit. SPLAT CLM was applied at 200 grams of product per acre nominal rate with treatment gaps (effective rate 140 grams per acre) in March 2012. Mating disruption lasted 6 weeks. Leaf mines were evaluated 3 times. Leaf mine incidence and severity were lower in the treated block 4 weeks after the first application, but there was no difference in mines by 10 weeks. Data from this trial and 4 other validation trials established in the spring of 2012 will be analyzed to determine longevity of mating disruption and the influence of applications on leaf mining and citrus canker.