*Department of Agril. Entomology, T.N.A.U., Coimbatore-641 008, India. E-mail: <alagarsp@yahoo.co.uk>
CICR, Regional Station, Coimbatore-641 003, India.
Part of Ph.D. thesis of first author submitted to T.N.A.U., Coimbatore.
The antibiosis mechanism of resistance to Nilaparvata lugens was studied by the nymphal survival, nymphal developmental period and growth index of nymphs. The mean nymphal survival was the lowest on ADT 45 (42.0%) followed by ASD 7 (43.0%) and ARC 10550 (44.0%). The overall mean nymphal developmental period was the highest on ARC 10550 (20.2 days) which was 8.27 days higher than TN 1. The growth index of BPH was low on ARC 10550, ARC 66540 W 1263 and KAU 1661.
Growth index, Nilaparvata lugens, Oryza sativa, Survival
