Citrus Rust Mite Control with Ac 303,630 on Texas Citrus, 1995

Different rates of experimental AC 303,630 and the standard acaricide Agri-Mek, alone and tank mixed with NR 435 spray oil, were compared for efficacy against CRM. Treatments were randomized and replicated 4 times on plots of 8 trees each in a 4-yr-old block of ‘Rio Red’ grapefruit planted on 15 X 24 ft spacing. Treatment sprays were applied 22 lun using an FMC 1229 single volute commercial sprayer with speed, nozzling and pressure calibrated for 250 gpa. At each count date, 50 fruit were randomly selected from the center 4 trees in each plot and examined for CRM in situ with a 10 X handlens. All live CRM (except eggs) were counted in two 1-cm2 lens fields on the shaded sides of each fruit and the two counts were averaged and recorded as one observation. In Nov, 60 randomly harvested fruit from each treatment replicate were evaluated for CRM feeding damage. If one third of the fruit surface area was damaged it was downgraded to process or juice fruit. The percent of downgraded fruit for each treatment was determined and expressed as percent russet.