Hussein Rasim Saboori Naji

ABSTRACT Laboratory and greenhouse experiments were conducted to evaluate the effectiveness of commercially available silicon oxide nanoparticle (SiO-NP) and zinc oxide nanoparticle (ZnO-NP) powder, applied at 5, 50 and 100 ppm, on the adult and egg stages of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), on tomato plants, Solanum lycopersicum L. (Solanaceae). The efficacy of SiO-NP and ZnO-NP on spider mites was assessed after 1, 3, 5 and 7 d after aplication in the greenhouse experiment. Results of the laboratory experiment showed that SiO-NP and ZnO-NP at 100 ppm caused 100% mortality among adult mites at 72 h after treatment and among eggs at 7 d post-treatment. SiO-NP and ZnO-NP at 50 and 100 ppm caused withered plants, but treatments at 5 ppm caused 85.4% and 100% adult mortality, respectively, and both treatments caused 100% egg mortality at 7 d after treatment in the greenhouse experiment. Average leaf damaged was 25% on the untreated plants but at 0.7% and 0.9% on plants treated with SiO-NP and ZnO-NP at 5 ppm, respectively. These results suggest that application of SiO-NP and ZnO-NP at 5 ppm is effective in controlling T. urticae.

A field study was conducted to evaluate the effectiveness of bitter melon oil at an average of 2 ml/L and Bifenthrin at a rate of 1 ml/L, as well as the interaction between Bifenthrin + bitter melon oil at a concentration of 1 ml/L and 2 ml/L of oil on adult and immature roles and eggs of the two-spotted red mite Tetranychus urticae Koch (Acari: Tetranychidae) on the okra plant Abelmoschus esculentus L (Malvaceae).The results indicated that the highest mortality rate for adult mites was when the treatment of the interaction between Bifenthrin + cognac oil with the mentioned concentration and the lowest mortality rate was when the control treatment (water only) reached 1,181 and 2,654 mite /leaf, respectively. There are significant differences between the mentioned treatments, and all treatments are significantly excelled on the control treatment in reducing the number density of adults. As for the non-adult roles, the results showed that the highest average of the number density of larvae and nymphs appeared in the control treatment and the lowest rate appeared in the Bifenthrin + cognac oil treatment with a concentration of 1 ml / liter for the pesticide and 2 ml / liter for the oil. It reached 4,305 and 2,117 caterpillars and nymphs/leaf. Also, the results indicated that there were significant differences between all the mentioned treatments, and all the treatments were significantly excelled on the control treatment. The results showed that there were no significant differences in reducing the number density of eggs between the Bifenthrin pesticide treatment and the interaction treatment between Bifenthrin + bitter melon oil, and indicated that the Bifenthrin pesticide treatment was excelled on the bitter melon oil treatment. All of the mentioned treatments were excelled on the control treatment in reducing the number density of eggs, where the lowest number density appeared in the treatment + Bifenthrin + bitter melon oil during the time period of 21 days of treatment, and the highest number density appeared in the control treatment during the same time period mentioned, as it recorded 1.282 and 2.807 eggs. /Leaf respectively.

Managing vegetable and fruit crops to reduce the incidence of diseases that affect crops after harvest