Vol. 12, Issue 4 (2023)

Author(s):
R Arulmozhi, A Muthuswamy and R Pushpa

Abstract:
Major rice insect pests that cause huge economic loss in Asia are stem borer, rice bug, leaf folder, leaf and plant hopper and gall midge (Sardesai et al., 2001). Among the eight leaf folder species recorded in India, Cnaphalocrocis medinalis was the most widely spread and the damage due to this species ranged from 18.3% to 58.4% depending on the stage of the crop at the time of infestation. In this study seventy four genotypes were screened for leaf folder damage following the procedure of IRRI (1964). The extent of leaf damage was recorded for plants in five hills selected randomly in all the three replications and were given grade from 0 to 3. Among the parents the female parent ACK 09009 was found to be highly resistant with mean scale of 1 with 6% leaf damage. The cultures ACK 09028 and ACK 09029 recorded highly susceptible with mean scale of 9 with 79 and 93% leaf damage respectively. Among the hybrids, the cross combinations involving ACK 09009, IR 8, IR 20 and CO 43 as female parent recorded moderately resistant with mean scale of 3 with range of 13 – 30% leaf damage. The expressions of resistance genes from parents to F1’s were similar to the findings of Gallagher (1994) and Ramasamy (1996).