Abstract
Tomato (Solanum lycopersicum L.) crop is susceptible to various insect pests of which whitefly (Bemisia tabaci Genn.) is the most predominant. Damage caused by whitefly may be directly through phloem feeding, or indirectly by transmission of viruses such as Tomato Yellow Leaf Curl Virus(TYLCV). Besides the feeding damage, this insect also exudes honey dew which favours the development of sooty mould. In severe infestation, this black coating is so heavy that its interference with the photosynthetic activity of the plant resulting in stunted growth. The incidence and spread of the Tomato Leaf Curl Virus (TLCV) was directly correlated with whitefly population on tomato field. The incidence of whitefly (Bemisia tabaci Genn.) population always remained higher on upper crop canopy of the tomato plant recording 58.37 % population followed by middle canopy (28.07% population) and lower canopy (13.56% population). Whitefly was most densely populated in the new young leaves of tomato plant on upper canopy. So sprays should be carefully taken on the upper canopy. Eight treatments were taken including one untreated control. Extracts of plant parts were done in methanol following standard method. Highly toxic chemical insecticides should not be used in tomato pest control as tomato is consumed as raw or after little cooking.From overall observation Imidacloprid resulted the best suppression of whitefly population (81.48% suppression) followed by avermectin (73.33%) and mixed formulation of azadirachtin with Spilenthes (71.65%) extracts and another mixed formulation azadirachtin with garlic (60.83% suppression). Three days after spraying, Imidacloprid resulted best suppression of whitefly population (82.17 % suppression) followed by avermectin (81.07 %) and mixed formulation azadirachtin with extract Spilanthes extracts (73.42 %) against whitefly. Azadirachtin individually did not produce higher results but when mixed with botanical extracts gave higher results of whitefly control. This may be recommended for general farmers’ use. The objective of this study is to determine the efficacy of microbial toxin, the plant extracts against whitefly and to formulate suitable control measure. Microbial toxin and botanicals are bio-pesticides having lower hazardous effects on human health and environment, and therefore, they can be incorporated in organic farming and Integrated Pest Management (IPM).
Keywords: Bio-pesticides neem, avermectin, Spilanthes, , organic farming
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