SOIL APPLIED INSECTICIDAL CONTROL OF CITRUS LEAFMINER , 2010

CLM causes significant damage to young leaves which also exposes leaf cuticle to the bacterium Xanthomonas citri responsible for the citrus canker disease. The trial was conducted at the University of Florida Southwest Research and Education Center in Immokalee, Florida, on 2-yr-old ‘Hamlin’ trees planted at 140 trees per acre in double-row beds running north-south and separated by a swale. Three adjoining rows were used for a CRBD with 12 treatments replicated 4 times. Each plot consisted of 5 trees that were pruned approximately once a month throughout the trial to encourage new growth (flushes) and provide suitable habitat for CLM larvae. Liquid treatments were applied by soil drench or foliar spray and granular treatments by incorporation into soil once on 25 or 26 Feb or a second time on 19 or 20 May (Table 1). Weeds, debris and leaf litter were removed from beneath each tree prior to soil applications. Granular insecticides were applied in a 16 inch furrow on the bed top side of each tree approximately 6-12 inches from the base of the tree. Soil drench applications were made by spraying 8 oz of solution to bare soil within 12 inches of all sides of the tree trunk using an EZ-Dose® sprayer operating at 45 PSI and a flow rate of 3.7 gpm. The same sprayer was used for foliar applications with a T-Jet 8003 nozzle and 8 fl oz of solution per tree canopy applying Movento at a concentration of 20 oz/100 gal. CLM larvae were monitored at approximately two-wk intervals depending on availability of suitable flush (Table 2). Five young shoots were taken per plot and 3 mid-stem leaves on each examined under a stereoscopic microscope.