Correlation studies and multiple linear regression analysis of rice leaf folder, Cnaphalocrocis medinalis (Guenee) incidence with biochemical characters of leaves of the rice varieties

Studies on “Correlation of rice leaf folder Cnaphalocrocis medinalis (Guenee) incidence with biochemical characters of leaves of the rice varieties” were conducted during kharif 2015 at Agricultural college farm, Bapatla, A.N.G.R.A.U. Andhra Pradesh. The effect of different biochemical characters like nitrogen content, chlorophyll content, protein content and silica content on per cent leaf folder damage were correlated and multiple regression models were worked out. Results indicated that biochemical parameters viz., nitrogen, protein and chlorophyll of leaf has positive correlation with leaf damage (r = 0.930, 0.930 and 0.898, respectively) while silica content was negatively correlated (r = -0.905) with per cent leaf folder damage. Results indicated that chlorophyll content was contributed 80.8 percent (R2) towards leaf infestation. With addition of nitrogen, protein and silica values R2 increased up to 87.29, 91.23 and 95.07, respectively. Thus, it was clearly evident that silica was the major contributing biochemical character for leaf folder resistance. In the present investigation, the high silica content in rice varieties offered resistance to rice leaf folder.