Preliminary Study of the Side Effects of some Pesticides on Natural Enemies in Apple Orchard in Al- Sweida Governorate.
2012
Zakaria Alnaser | abd alnabi Bashir
This research was conducted to study the side effects of some insecticides (mineral oil, dimethoate, chlorpyrphos-ethyl) and several fungicides such as (sulphur, thiophanate- methyl and Copper Oxychloride) on the natural enemies in apple orchared in Al-Sweida Governorate, during the season 2006-2007. The results revealed that winter spray of pesticides has not any negative effects on natural enemies on apple trees. Where the April treatment caused significant reduction in number of the studied predators : Coccinellidae, Syrphidae and Chrysopidae, reducing the parasitism ratio of Aphelinus mali and Aphidius spp. However, Chlorpyrphos-ethyle+ sulfer gave the highest reduction in this ratio. Furthermore, treatment during May reduced number of predators and the ratio of parasitism in both treatments. Repeated spray with pesticides caused an accumulative effect on the investigated parasitoids and predators.
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