EFFECTS OF INTEGRATED WHITEFLY POPULATION (Bemisia tabaci Genn., Homoptera: Aleyrodidae) MANAGEMENT PRACTICES ON TOMATO SEEDLINGS PRODUCTION. RENACIMIENTO. CHIRIQUI. PANAMA. 1996.

Abstract

An experiment was established with the objective to determine the effects of integrated management practices of whitefly population on the growth and development of tomato seedlings. Treatments were evaluated using a Complete Randomized Block Design with experimental field plots disposed in a split split plot arrange with the seedlings production system (under open field conditions and under polyethylene roof) as main plot, the seedbed protection method (micro tunnel with Lutrasil Thermoselect® covering versus Imidacloprid insecticide) as subplot, and plant population in terms of the grams of seed per square meter (0.5, 1.0 and 2.0 g/m²), as sub sub plots. The experimental variables were: number of transplantable seedlings at 22 days from seed germination and living adult whitefly population on all leaves of each plant in each experimental plot. The analysis of variance for the number of transplantable plants showed significant differences (P<0.05) between main plots (seedlings production systems) and highly significant ones (P<0.01) at sub plots (seed protection methods) and sub sub plots (plant population) levels, respectively. The interactions seedlings production system (SPS) X seedbed protection method (SP), SPS X plant population (PP), SP X PP, and SPS X SP X PP, also were highly significant (P<0.01). The whitefly population variable also showed highly significant differences (P<0.01) within sub (seedbed protection method) and sub sub (plant population) plots, but not within main plots (seedlings production system). The interaction polyethylene roof + Imidacloprid (0.07 g.a.i./g of seed) and a plant population of 2.0 g of seeds/m² produced the higher amount of transplantable seedlings (268 plants/m²) and totally eliminated the adult whitefly population. It may be concluded that, under the experimental conditions, the implementation of this interaction optimized the growth and vigorous development of tomato seedlings, free of Gemini virus transmitted by the whitefly.