Influence of Certain Insecticide Regimens Against Bollworms in Cotton Fields in Egypt

Document Type : Original Article

Authors

1 Pesticide Chemistry Dept., Faculty of Agriculture, Alexandria University

2 Plant Protection Research Institute, ARC, Bacous, Sabahia, Alexandria, Egypt.

Abstract

Comparative studies were carried out in five regimens to find out the best solution for cotton bollworm problems during cotton seasons of 2006 and 2007. These regimens were (1) of chlorpyrifos, chlorpyrifos, deltamethrin and deltamethrin. (2) of carbosulfan, spinosad, chlorpyrifos and deltamethrin. (3) of carbosulfan, carbosulfan, deltamethrin and deltamethrin. (4) of deltamethrin, chlorpyrifos, deltamethrin and carbosulfan. (5) of spinosad, chlorpyrifos, spinosad and carbosulfan. The sequence No. 5 achieved high efficacy against Pectinophora gossypiella which gave the reduction percentage of 87.6 and 88.1 while, the sequence No. 4 achieved superior efficacy against Earias insulana which gave 89.3 and 92.5 reduction of infestation throughout season 2006 and 2007, respectively. The statistical analysis decleared that regimen 4 and 5 were comparable, meanwhile they were significantly better than regimens 1, 2 and 3. The highest effective regimens 4 and 5 (gave about 87% infestation reduction) were started and mediated with pyrethroid compound (deltamethrin) and bioinsecticide (spinosad), respectively. The repetition of the same insecticide twice in a regimen might increase, decrease or has no effect on the insecticide efficiency against cotton bollworms.

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