Evaluation of botanical insecticides to control whitefly (Bemisia tabaci Gennadius) and tomato flee (Halticu ssp) in tomato (Solanum lycopersicum Mill.), in Nicaragua

Abstract

The whitefly-virus complex (Bemisia tabaci)-Geminivirus and Halticus sp. are the main cause of economic losses in tomato (Solanum Lycopersicum Mill) in the municipality of Tisma, Masaya. Due to this situation, a study was conducted to evaluate the effectiveness of botanical insecticides such as: Chile + Garlic + Soap, Madero Negro, Chrysanthemum, alcoholic extract + Chili and alcoholic extract + Chili + Garlic in the period from December 2013 to February 2014. Of the treatments evaluated, the lowest number of whiteflies per plant and lower percentage of severity at one hundred days after transplanting was obtained with the treatment Alcoholic extract+Chili+Garlic. The treatment Madero Negro had the highest effectiveness in managing populations of Halticus sp. The economic analysis showed that the highest yield was obtained by the Alcoholic extract+Chili+Garlic with 34 685.18 kg/ha-1 followed by the treatment Chili+Garlic+Soap with 30 614.28 kg/ha-1. According to the marginal return analysis, this proved that the treatment Chili+Garlic+Soap is the one who obtained the best marginal rate of return with 1 476 %, which means that USD 14.76 is obtained for every dollar invested. According to samples of tomato tissue and whiteflies insect samples sent for analysis to at the University of Arizona in Tucson, this determined that the 66.66% of white flies samples from Tisma are indigenous whitefly, biotype “A”, and the 33.33% corresponds to the “B” biotype, the one that is more aggressive than “A”. The Begomoviruses analysis found that severe curl leaf tomato (ToSLCV) with at least 96% and golden mosaic virus of pepper (PepGMV) with 98% identity were identified in this study.