Abstract

                                Experiments were conducted during 2011 and 2012 to evaluate the biological efficacy of lufenuron 5.4 EC at 20, 30, 40, and 60 g a.i./ha against diamond back moth (DBM), Plutella xylostella L. in cabbage in tropical (Jahirnayakanpalayam, Coimbatore) and temperate regions (Kotagiri, Ooty) of Tamil Nadu. The results revealed that lufenuron 5.4 EC, indoxacarb 15.8 EC and cartap hydrochloride 50 SP were effective in reducing P. xylostella population in cabbage. Lufenuron 5.4 EC at 60 g a.i./ha showed the highest mortality in tropical (71.45%) and temperate (74.80%) conditions against P. xylostella. Lufenuron 5.4 EC at all the doses was comparatively less toxic to Cotesia (8.74 - 16.12%) in tropical and (9.59 – 14.44%) temperate regions on compared to standard check indoxacarb. Cartap hydrochloride was more toxic to Cotesia by recording a cumulative mean per cent reduction of 44.83, 39.37 at tropical and 47.56, 36.50 at temperate regions, respectively. Foliar application of lufenuron at 30, 60 and 120 g a.i./ha in cabbage at both regions did not cause any phytotoxic effects. The marketable yield recorded in lufenuron 5.4 EC at 60 g a.i./ha was 63.12 t/ha in tropical and 83.10 t/ha in temperate region which was also significantly higher than other treatments.

Key words : IGR, lufenuron, Plutella, bioefficacy, phytotoxicity, Cotesia, yield