Pear, Residual Control of Pear Rust Mite with Safer'S Soap, 1990

Mature Bartlett' trees in Fennville, MI were sprayed with an FMC 1029 airblast sprayer at 150 gpa of finished spray. Trees were arranged in a completely randomized design of single trees replicated 4 times. Applications of all materials were made as indicated in the table on 11 May (PF), 23 May (IC), 5 Jun (2C), and 28 Jun (4C). Dates of evaluation were 29 May, 6 Jun, 12 Jun, 19 Jun, 26 Jun, 5 Jul, 10 Jul, 17 Jul, 24 Jul, and 7 Aug. At each evaluation, 50 leaves per replication (200 per treatment) were picked and brushed in a mite brushing machine and examined under a stereo microscope for rust mite adults. At harvest, 50 fruit per replicate (200 per treatment) were harvested and examined for russetting damage from PRM. Russetting evaluations were based on visual inspection, with the scoring criteria listed in the table.