Author(s): MA DELING , GORDH GORDON , ZALUCKI M P
Interpretive Summary:
We tested the effectiveness of biopesticides and chemicals applied to cotton during its reproductive phase against the bollworms Helicoverpa armigera (Hubner) and H. puntigera Wallengren, as well as predators at Dalby, Queensland, Australia. We tested the neem-seed extract, azadirachtin, at rates of 30g, 60g and 90g per hectare. We found moderate rate-dependent control was obtained in plots treated with azadirachtin. Other plots were treated with Talstar EC (bifenthrin). Applications of bifenthrin achieved the best results, followed by treatment with chemicals (methomyl, bifenthrin, thiodicarb and endosulfan) alternated with biological insecticides (neem oil, Azadirachtin and Bacillus thuringiensis kurstaki var. berliner). Predators (lady beetles, lacewings, spiders and bugs) were not sensitive to Azadirachtin or Bt applications. In contrast chemicals were very destructive of predators. All treatments provided some protection from both species of bollworms. The effect of azadirachtin on bollworms was shown in a higher yield of seed cotton harvested from azadirachtin-treated plots compared with the control.
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