Evaluation of Preventive and Rescue Sprays for Spwf on Potted Tomatoes, 1990

Abstract

Abstract Potted tomato plants were used in a greenhouse study to evaluate specific insecticides as preventive and rescue sprays for SPWF. Each treatment and check was replicated four times as a preventive and rescue spray. Preventive applications were initiated prior to SPW infestation establishment. Four applications were made on a weekly basis starting 10 Sep. Plants receiving rescue sprays were treated four times on a weekly basis starting 12 Oct (SPWF was well established at this time). Treatments were evaluated three days after the final application for each group. Treatments were diluted at indicated rates for application in 100 gal/acre. The dilute sprays were applied with a hand held atomizer. Plants were placed on a turntable and turned as they were being sprayed to insure thorough coverage. SPWF populations were monitored by sampling three leaves from each plant (2nd, 4th and 6th leaf from the cotyledons). Each leaflet of the trifoliate was placed under an index card containing two 1/4 inch hole punches, examined under magnification, and all eggs, immatures and pupal cases seen within the hole punches were recorded as number per leaf (six hole punches). Because of extreme unequal variation associated with SPWF distribution, data were transformed using Log X + 1 for analyses. Data presented are means for all three locations on the plant and analyzed with location as an independent variable.