author(s)
Uddipana Shandilya, Purnima Das and Dibyarishi Bhattacharjya

abstract
Five doses of gamma radiation (100Gy, 150Gy, 200Gy, 250Gy and 300Gy) along with a control and check variety were screened against rice leaf folder, Cnaphalocrocis medinalis Guen. (Pyraustidae: Lepidoptera) at Assam Agricultural University, Jorhat-13 during kharif season of 2018 and 2019. The field experiment was laid out in a randomized block design and the entire experiment was conducted organically. The irradiation doses were evaluated based on the Standard Evaluation System (SES) for rice with a scale of 0 - 9. Infestation of Cnaphalocrocis medinalis ranged from 5.49±1.93% to 38.50±1.24%. Infestation was lowest at 200Gy (14.84±0.98%) and highest at 300Gy (24.80±2.01%). The doses 100Gy, 150Gy and 200Gy were recorded as Moderately Resistant, 250Gy and 300Gy as Moderately Susceptible against C. medinalis infestation according to SES, IRRI.