Vol. 11, Issue 7 (2022)

Author(s):
A Anvesh, S Jeyarajan Nelson, A Suganthi, D Uma, P Anusooriya and J Kousika

Abstract:
An experiment was conducted to detect the toxicity of column chromatographic fractions of sweet flag, Acorus calamus extract against pulse beetle, Callosobruchus maculatus. A total of 105 fractions were eluted from 7 combinations of 4 solvents viz., hexane, dichloromethane, ethylacetate and methanol. Among these, 20 fractions eluted using hexane and hexane+dichloromethane combination showed insecticidal activity. These 20 fractions were subjected to Ultra High performance liquid chromatography to check the presence of active compound i.e, β-asarone. The results revealed that only 8 fractions had β-asarone content and it ranged between 56 and 285µg/ml. The fractions with β-asarone caused 65.00 to 85.00 per cent mortality within 24 hours after treatment (HAT) while the mortality was between 25.00 and 55.00 per cent in the fractions which did not contain β-asarone. However, cent per cent mortality was observed in all the 20 fractions at 72 hours after treatment. Oviposition in seeds treated with fractions was reduced to the tune of 82.50 to 100.00 per cent. No adult was emerged from the seeds treated with hexane and hexane+dichloromethane combination fractions of sweet flag extract while 85 number of adults emerged from untreated seeds.