Insecticidal Control of Cotton Aphid in Citrus, 2019

A field trial was conducted in a 5-yr-old ‘Tango’ mandarin block at the Lindcove Research and Extension Center, Exeter, California. Treatments were assigned to in 10 individual trees per treatment in an RCB design on 11 Mar 2019 based on pretreatment aphid counts and sampling was conducted for 3 wk. Insecticides were applied in 100 gpa at 250 psi on 25 Mar 2019 using a 100-gal high-pressure D30 diaphragm pump sprayer with mechanical agitation with a D6 nozzle on a hand wand. All treatments were applied with 0.25% Dyne-Amic. For precount samples, the number of aphid-infested terminals out of 20 terminals randomly selected from around the tree were counted. On all other sampling dates, the number of aphid-infested terminals out of 25 terminals were counted. The mean numbers of infested terminals were compared between treatments using one-way ANOVA after testing for an NS block effect. Means were separated according to Fisher’s protected least significant difference test (P = 0.05) after asin(sqrt(x)) transformation of the data.

Movento and Sefina treatments significantly reduced the percentage of aphid-infested terminals in the three post treatment samples and Beleaf reduced aphids significantly in one post-treatment sample (Table 1).¹

Footnotes