K Venugopala Reddy
Articles written in Proceedings – Animal Sciences
Volume 94 Issue 1 January 1985 pp 37-48
A total of 1070 rice varieties, mainly from Assam Rice Collection, were evaluated to identify better sources of resistance to brown planthopper,
All the resistant and moderately resistant varieties were relatively less preferred by nymphs and there was a positive correlation between the number of nymphs settled and the damage score. Test varieties non-preferred by adult insects for feeding and shelter were also less suitable for oviposition with the exception of ARC 13854, and ARC 14766A. On resistant varieties the nymphal survival was much lower (18·5–28·4%) and nymphal duration was prolonged by 5–7 days as against those on the susceptible check. Results of probing behaviour tests indicated that resistant varieties received more number of probing punctures (80–121) than the susceptible check (31). Further, insects caged on resistant varieties quickly lost their body weight while those on the susceptible check registered gain in weight. Honey dew excretion by brown planthopper adults on resistant varieties was 6·6 to 11·9 times less than that on susceptible T(N)1. Selected varieties showing moderate damage reaction (ARC 5918, ARC 10443, ARC 13984, ARC 14529 and ARC 14864) exhibited more feeding marks, greater amounts of excretion, and higher gain in body weight of the insects, thus confirming a moderate degree of resistance. Based on various parameters, ARC 5780, ARC 5988 and ARC 14394 were comparable to resistant check, Ptb 33 in level of resistance. No association of Lemma and Palea colour with brown planthopper resistance was observed in the rice varieties tested.