CONTROL OF ASIAN CITRUS PSYLLID WITH FOLIAR APPLICATIONS OF INSECTICIDE IN ORANGES DURING BLOOM, 2008

ACP is a key pest of citrus in Florida, due primarily to its interaction with Huanglongbing or citrus greening disease. ACP vector’s the bacterium, Candidatus Liberibacter asiaticus responsible for greening or “Huanglongbing” disease of citrus. The experimental block at the Southwest Florida Research and Education Center, Immokalee, Florida consisted of 12-yrold sweet orange ‘Valencia’ trees planted on double-row raised beds at a density of 132 trees/acre. Trees were irrigated by micro-sprinklers and subjected to conventional cultural practices. Bed sides of the trees were pruned manually to induce new flush and encourage ACP infestation. Seven treatments and an untreated check were randomly distributed across 4 replicates in 15 rows that included a buffer row after every treated row. Each replicate contained 2 treated rows of 20 trees divided into four 5-tree plots. Treatments were applied on 11 Mar 2008 using a Durand Wayland 3P-10C-32 air blast speed sprayer with an array of six # 5 T-Jet stainless steel cone nozzles per side operating at a pressure of 200 psi delivering 150 gpa at a tractor speed of 1.5 mph. The post treatment evaluations were made on 17, 24, and 31 Mar and 17 Apr. Three trees were sampled in each five tree plot. Adult ACP density was estimated by counting the insects falling on a clipboard covered with an 8 1⁄2 × 11 inch white paper sheet placed under randomly chosen branches which were tapped 3 times with the hand to make a count for one tap sample. Four tap samples were conducted per tree. Ten randomly selected shoots were observed on each tree and the number infested with ACP eggs or nymphs recorded. Adult density and shoot infestation were recorded on the first three sampling dates. On 31 Mar, fourth and fifth instar nymphs on the flushes were also counted. On 17 Apr, two flushes were randomly selected on each tree and the number of leaves with ACP feeding damage was noted on five randomly selected fully opened soft leaves on each flush. Data were subjected to ANOVA to evaluate treatment effects on ACP and means were separated using LSD contingent on a significant treatment effect (P = 0.05). Numbers of ACP adult were transformed by log(x+1) prior to analysis but actual means are presented.