Abstract

                                A field experiment was conducted during the kharif 1986-87 to study the effect of different population levels of white backed planthopper (WBPH) Sogatella furcifera (Horvath) on five rice varieties viz., ARC 10550 (resistant), Co 22, Co 13, Triveni (moderately resistant) and ACM 9 (locas check). The seedling screening bulk test indicated similar reaction to S. furcifera in the resistant and moderately resistant varieties. However, field screening showed that Triveni was more tolerant than other varieties, as evidenced from the low reduction in the mean plant height and plant weight. This clearly indicates the ability of Triveni to survive and produce more number of productive tillers even at higher population levels of WBPH. On the other hand, a minimum population of 25 WBPH/plant was sufficient to cause a significant reduction in the plant vigour. height and weight in all the varieties.

Key words : WBPH, Population Levels, Rice Varieties, Tolerance.