Chemical control based on Azadirachta indica in Bemisia spp. in the cultivation of zucchini (Cucurbita pepo)

Abstract

The whitefly Bemisia spp. is a sucking insect, considered a polyphagous pest. In addition to the damage caused directly by sucking sap and the injection of toxins, this insect is responsible for the transmission of viruses and physiological changes in the plant, as silver the zucchini. The objective was to evaluate different doses of Neem, for the control of Bemisia in italian zucchini, in the dry season. We tested six treatments repplicated five times: (1) control, without treatment, (2) application of the Neem extracts in dosage of 50 mL per 10 liters of water, (3) application of the Neem extracts in dosage of 70 mL per 10 liters of water; (4) application of the Neem extracts in dosage of 80 mL per 10 liters of water; (5) application of the Neem extracts in dosage of 90 mL per 10 liters of water; (6) implementation of Thiametoxan (Actara – standard control), the dosage of 1.5 mL per 10 liters of water. The evaluations were conducted in 12 plants per plot after 1, 3, 5 and 7 days after the applications of treatments. One day after the application of the Neem extract, the control statistically differed of the all the treatments. However, the low residual power of the extract and the concentrations used allowed a significant increase in the number of whitefly in the plots, over the course of the day. The best dosage of the Neem extracts to control the whitefly in the culture of the Italian zucchini is 900mL/100L water