Rust Mite Control on Texas Citrus, 1983

Experimental SLJ-0312, MK-936 + Gulf Spray Oil, Advantage, and Advantage + Ethion were compared to several standard acaricides for efficacy against citrus rust mite (CRM). A 22-year-old grapefruit orchard (16 by 22 ft spacing) was utilized; treatments were arranged in a randomized block design with two replicates, each consisting of 2 rows of 13 trees, i.e. 52 trees per treatment. Applications were made on 17 May by commercial air blast sprayer at 1 mph with nozzling and pressure adjusted for a spray volume of 250 gal/acre. At each count date 50 fruit per replicate were randomly selected and examined in situ with a 10X hand lens. All CRM were counted in two, 1 cm2 lens fields on the shaded side of each fruit. At harvest, 100 fruit per replicate were evaluated for CRM damage and expressed as percent russet, i.e. fruit surface damage severe enough to be downgraded to US #2 fresh or process fruit.