Pear, Early Season Control of Pear Psylla and Pear Rust Mite, 1996

Abstract

Abstract Mature ‘Bartlett’ trees at the Trevor Nichols Research Complex in Fennville, MI (Pear 1 Block) were sprayed at a rate of 100 gpa with an FMC 1029 airblast sprayer. Trees were arranged in a CR design of single trees replicated 4 times. All materials were applied as indicated in the table on 4 Jun (IC) and 17 Jul (4C, PP Threshold of 0.3 nymphs per leaf). Streptomycin, Benlate, Penncozeb, Rubigan, Captan, and Funginex were applied to all treatments separately. Dates of PP and PRM evaluation were 19 Jun, 2 Jul, 15 Jul, and 8 Aug. At each evaluation, 50 leaves per replicate were picked, brushed in a mite-brushing machine and then examined under a stereo microscope for PRM adults. Twenty-five leaves per replicate were also evaluated under a stereomicroscope for PP nymphs and eggs. Mean data are reported as PRM adults per leaf, and PP nymphs or eggs per leaf. Harvest fruit evaluations were made on 27 Aug by picking 25 fruit randomly from the periphery of the tree from each replicate per treatment. They were examined for sooty mold from PP and PRM russetting. Sooty mold and russetting evaluations were based on visual inspection, with the scoring criteria listed in the table.