Pacific Spider Mite Control in Almond, 2014 *

This trial evaluated the effectiveness of miticides for Pacific spider mite treatments in almond. The field trial was conducted in Shafter, Kern Co., CA in a 6-yr-old orchard with 20 × 22 ft spacing that contained alternating rows of the varieties “Nonpareil” and “Monterey”. Plot size was three trees long by one row wide. The plots were organized into an RCB design with 4 blocks of 10 treatments and an untreated check. Treatments were applied on 16 June to individual trees with a hand gun at 150 psi with a water volume of 200 gpa.

Mite densities were evaluated in each plot prior to treatment on 13 June and then on 19 June, 23 June, 30 June, 7 July, 14 July, and 21 July. On each sampling date, a total of 20 leaves were collected per plot. Leaves were transported to a laboratory where motile Pacific spider mites (larvae, nymphs, and adults) were counted. For each evaluation date, the average number of mites was analyzed by analysis of variance using transformed data (square root (x + 0.5)) with means separated by Fisher's Protected LSD ( P =  0.05).

Mite density prior to treatment was not significantly different compared with the untreated checks ( Table 1 ). All treatments were not significantly different than the untreated check on 19 June, 23, June, 30 June and 21 July evaluation dates. On 7 July, Envidor, Fujimite XLO, Nealta, Vigilant, and Zeal had significant reductions in mite densities compared with the untreated checks. On July 14, Envidor, Fujimite XLO, Onager, Vigilant, and Zeal had significant reductions in mite densities compared with the untreated check.

Author notes