Persistence, Relative Efficacy and Phytotoxicity of Lantana camara Var. Aculeata (L.) Moldenke Leaf Crude Extracts in Hexane against Plutella xylostella L. In Cruciferous Vegetables

The present investigation was carried out to evaluate the phytochemicals from hexane extracts of wild sage, Lantana camara var. aculeata (L.) Moldenke. Out of the six concentrations tested against diamondback moth larvae on cauliflower, 6, 8,10 % were found to be more persistent than1 and 2% against 2, 3 and 4th instar of DBM larvae. The order of efficacy of different treatments was hexane crude extracts 10% > 8% > 6% > 4% > 2%> 1%. However, the highest PT values to the extent of 7 days was observed in 6 per cent, when applied against second, third and fourth instar larvae of DBM on cauliflower and followed by 4 per cent upto 7 days without phytotoxicity. Moreover, 8 and 10% concentrations gave significant mortality but it caused phytotoxicity from 5th days after spraying in cabbage and cauliflower. The effective biological action of the phytochemicals against the larvae varied with different instars. The crude extracts were biologically effective for 7 to14th day after treatment against second instars and their index of persistent toxicity was higher than that of third and fourth in stars. Phytotoxicity (%) of crude extracts of 8 and10% concentrations caused leaf tip injury as observed in both cauliflower (33.00 and 49.50%) and cabbage (2.0 and 9.0) potted plants.