Document Type : Original Article
Authors
1
Department of Plant Protection, Zagazig University, Egypt
2
Department of Pedology, Desert Reseach Center, Cairo, Egypt
Abstract
Yellow mite, Polyphagotarsonemus latus (Banks) is the greatest destructive pest on pepper plants in Egypt. The efficacy of bifenthrin 25% EC against the yellow mite Polyphagotarsonemus latus (Banks) and its impact on natural enemies (predatory mites) were assessed through three field experiments conducted at Wadi Al-Mollak, East Delta, Egypt for three seasons. The treatments included bifenthrin applied at the rate of 40, 50, 60, 80, 100, 160 and 320g a.i.ha-1compared with standard check dicofol at 290 g a.i.ha-1 and an untreated check. Obtained percentages of reduction in yellow and predatory mites were 1, 3, 5, 7, and 14 days after spraying. The initial population of mites/leaf before first spraying ranged from 3.83 to 4.91 in all the treatments without any significant difference. The dose of 80 g a.i.ha-1 of bifenthrin had a significant effect on the entire treatments units. The standard check dicofol at 290 g a.i.ha-1 recorded 71.81, 73.63 and 67.76% of reduction in mite population at first, second and third experiment after first spraying, respectively, and 74.76, 85.09 and 76.09% of reduction at first, second and third experiment after second spraying, respectively. The initial population of predatory mites, Amblyseius ovalis ranged from 0.70 to1.11 mites/leaf in the entire treatment. Dicofol at 290 g a.i.ha-1 caused the highest reduction of 49.77, 56.75 and 54.56 % in the first, second and third experiment, respectively. The lowest dose of bifenthrin at 40 g a.i.ha-1 was the least toxic treatment, The toxicity order for different bifenthrin doses against predatory mites and were 320 > 160 > 80 > 100 > 60 > 50 > 40 g a.i.ha-1. Dicofol was highly toxic to A. ovalis compared to bifenthrin treatments. Even after 14 days of spraying nearly 50% reduction was noticed in the case of dicofol. It can be conducted that bifenthrin was found to be relatively safer than dicofol because most likely due to its residues being longer than bifenthrin.
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