Population Buildup of Brown Planthopper, Nilaparvata lugens on Selected Rice Genotypes

Studies on population buildup of Nilaparvata lugens on some selected rice genotypes were carried out in the glasshouse. Population buildup is a reliable parameter in evaluating the degree of resistance of a genotype. The emergence of brown planthopper (BPH) macropterous form was higher on the resistant and lower on the susceptible genotypes. Similarly, the per cent male emergence was higher on the resistant genotypes titan on the susceptible one. The population buildup of first generation nymphs was the lowest on ARC 6650 by recording 186.4 and 106.8 nymphs per plant, on 30 and 60 day old plants, respectively. Thirty and sixty day old plants of ARC 10550, KAU1661 and ARC 6650 took significantly longer period (27 to 31 days) for wilting compared to TNI (18.2 days) due to low population buildup. Inspite of supporting higher population of first generation nymphs. KAU 1661 took longer time for wilting.