Full Season Evaluation of Acaricides for Rust Mite Control, 1980

Two rates each of the experimental acaricides, FMC 35001 and UC 55248, were compared to chlorobenzilate and Ethion for efficacy against citrus rust mite (CRM). A 20-year-old grapefruit orchard (16 x 22 ft tree spacing) was utilized; treatments were arranged In a randomized block design with 3 replicates, each consisting of 2 rows of 6 trees, i. e. 36 trees/treatment. Treatments were first applied on Apr 22 and reapplied on Jul 17 and Oct 8 using a commercial airblast sprayer. Speed of the sprayer was I mph with nozzle adjustment and pressure regulated to apply 250 gal/acre. CRM counts in Apr and May were on leaves (lOO/replicate) and thereafter on fruit (100/ replicate) using a lOx handlens with a l-cm2 grid. At harvest 100 fruit/treatment were evaluated for CRM damage and expressed as percent russet. i.e. fruit with damage severe enough to be downgraded to US #2 fresh or process fruit.