Population abundance of whitefly, Bemisia tabaci (Genn.), on chilli and other vegetable crops under glasshouse conditions

Whitefly (WF), Bemisia tabaci (Genn), is one of the most damaging pests for several vegetables in Malaysia which affects plant vigour, transmits geminiviruses and reduces crop quality. This study estimated the population abundance of B. tabaci on chilli, Capsicum annuum MC 11 alone, MC 11 planted with brinjal, Solanum melongena MT e1, tomato, Lycopersicum esculentum MT 1 or okra, Abelmoschus esculentus MK BE1 and MC 11 planted with a combination of all the other crops under glasshouse conditions. WF adults, egg and nymph samples were obtained every 4 days from the underside of the leaf (abaxial) on the upper, middle and lower strata of the plant for one month. The total mean numbers of WF adults, eggs and nymphs were significantly higher (p 0.05) on chilli in the monoculture experiment than on chilli in multiple crops experiment with okra, tomato and brinjal. Results also showed that the population of WF adults and eggs were significantly higher in the upper stratum than in the middle and lower plant strata. Interestingly, the number of nymphs was higher in the middle stratum than in the other strata in all treatments. This phenomenon indicated that mixed crops can lower pest populations and indirectly reduce virus disease incidence