Effect of nutrient and pre-infested brinjal, Solanum melongena by whitefly and aphid on population dynamics of whitefly, Bemisia tabaci

摘要

This study investigated the consequence of nutrient concentration levels and pre-infestation of brinjal (Solanum melongena) plant (by whitefly and aphids) on population of whitefly (Aleyrodidae; Hemiptera) over two cropping periods. Both factors, nutrient levels and pre-infestation by pests could also change plant-pest relationship especially with herbivorous insect pests. Variation in nutrient levels applied to the plants could influence different physiological performance of the plants which subsequently affected whitefly population. Populations of whitefly were higher following increasing levels of nutrients in non-pre-infested (control) plants. Lower whitefly populations were observed on whitefly pre-infested brinjal plants compared to aphid pre-infested and control plants. Pre-infested plants were suspected to induce productions of secondary metabolites as a chemical defense system thus lowering the number of whiteflies on them. Considering other management technique in controlling whiteflies on brinjal such as optimum nutrient supplement as plant growth progress and good pest care during seedling stage was proposed.