Comparative Effectiveness of New Insecticides against Spodoptera litura in Tobacco Nurseries
U. Sreedhar*
ICAR-Central Tobacco Research Institute, Rajahmundry - 533 105, Andhra Pradesh, INDIA
DOI: NIL
Keywords: Insecticides, IGRs, Nicotiana tabacum, Spodoptera litura, Tobacco
Abstract
Tobacco caterpillar, Spodoptera litura F. is the key pest of tobacco nurseries and it is one of the major problems in successful production of healthy tobacco seedlings required to realise optimum yield and quality tobacco leaf. Insecticides chlorfenapyr 10 SC @ 0.01%, metaflumizone 22 SC @ 0.04%, spinosad 48 SC 0.01% and IGRs novoluron 10 EC @ 0.01% & lufenuron 5 EC @ 0.006% were evaluated against S. litura in tobacco seed beds in a replicated experiment in comparison with emamectin benzoate 5 SG @ 0.0025% and untreated control for two seasons. Emamectin benzoate 0.0025% recorded least seedling damage followed by chlorfenapyr 10 SC @ 0.01%. The seedling damage in the treatments of emamectin benzoate and chlorfenapyr was on á par with each other. The studies on persistent residual toxicity of the insecticides showed cent per cent mortality up to 8 days in emamectin benzoate @ 0.0025% and 6 DAS in chlorfenapyr @ 0.01%. The period of persistency was 20 days in emamectin benzoate and 16 days in chlorfenapyr treatment. The mean persistent toxicity and persistent toxicity index were 62.84 & 1256.80 for emamectin benzoate 5 SG @ 0.0025% and 71.95 & 1151.20 for chlorfenapyr 10 SC @ 0.01%. Chlorfenapyr 10 SC @ 0.01% can be used for management of S. litura in tobacco seed beds along with emamectin benzoate 5 SG @ 0.0025%.
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