Evaluation of the efficacy of some types of plant oil extracts in controlling the whitefly Bemisia tabaci on eggplant in green houses

The whitefly Bemisia tabaci is an economically important pest that causes significant damage to eggplants and is difficult to control. The study was conducted to evaluate the efficacy of 1 % and 3 % oil extracts from mustard, eucalyptus and castor plants in controlling the whitefly B. tabaci on eggplant plants in greenhouses during the 2024–25 growing season. The study results showed that all oil extracts at both concentrations significantly reduced the number of adult insects which captured on the yellow sticky traps, where the population density of caught insects decreased in the experimental greenhouse, where 102 and 31 insects were caught respectively, compared to an increase in their numbers in the control, where reached 158 and 236 insects during April and June respectively. The results also showed an effective impact on reducing the number of nymphs on the plants and a 3 % concentration of all oil extracts was more effective in reducing nymph numbers, as the nymph counts at a 1 % concentration were 21.17, 13.17 and 10.57 nymphs and at a 3 % concentration, they were 17.75, 7.08 and 6.75 for mustard, eucalyptus and castor oils respectively, while in the control, there were 72.50 nymphs per leaves after 28 days of treatment. The highest relative efficacy was achieved for mustard, eucalyptus and castor oils at 3 % concentration 28 days after treatment, reaching 81.18 %, 86.70 % and 87.93 % respectively, while the chemical pesticide reached 81.83 %. The results showed that the reduction in whitefly populations was reflected in improved yield-related traits, including the number of flowers, the percentage of fruit set and the number and weight of fruits, compared to its decline in control treatment.