Control of Twospotted Mites on Greenhouse Tomatoes, 1997

Two trials were conducted for evaluating the efficacy of several miticides for control of twospotted mites, Tetranychus urticae Koch, on greenhouse tomatoes. The materials evaluated and the rates at which they were applied included Alert 2 SC (0.050, 0.075 lb [AI]/acre), Agri-Mek 0.15 EC (0.009 lb [AI]/acre), Savey 50 WP (0.095, 0.165 lb [AI]/acre), and Kelthane MF (0.37 lb [AI]/acre). Kelthane MF was substituted for Agri-Mek 0.15 EC in the 2nd trial. Plots were arranged in a RCB design. Each treatment was replicated 3 times with 6 plants per replication, for a total of 18 plants per treatment. Tomatoes of the ‘Match’ variety were used in the 1st trial, while tomatoes of the ‘Trust’ variety were used in the 2nd trial. Pre- and post-treatment counts were done by removing a leaflet from each of six plants per replication, for a total of 18 leaflets per treatment. The leaflets were removed from a leaf selected at random midway up the plant. The leaflets were taken back to the laboratory where the number of mites and eggs were counted. Treatment applications were made using a 3-gallon, hand-held compressed-air sprayer. The plants were sprayed to runoff, ensuring that both the upper and the lower leaf surfaces were thoroughly covered. Check plants were sprayed with water only.