Studies on components of resistance in maize genotypes to Chilo partellus (Swinhoe)

Five maize genotypes viz., CML 67 and CM 500 (resistant), PMH 1 and JH 3459 (susceptible) and Basi local (highly susceptible) were evaluated for their response to Chilo partellus under laboratory and field conditions. These cultivars were observed in no-choice and dual-choice tests for oviposition preference, leaf-feeding responses of neonate larvae on excised leaves and for their resistance in the field under artificial infestation conditions. Different components of resistance were determined from field studies using the regression of FPLI (y) on C. partellus larval dry weight (x) for all the cultivars. The number of egg masses and total number of eggs per plant on different genotypes did not differ significantly in no choice test, however it was significantly more on Basi local than CML 67 in dual-choice test. The leaf area fed, larval weight gained, leaf injury ratings, larval recovery and stem tunneling was less in CML 67 and CM 500. However, larval survival did not vary among different cultivars. Data on regression of FPLI indicated that antibiosis and tolerance were present in cultivars CML 67 and CM 500 but absent in Basi local. The cultivars PMH 1 and JH 3459 showed the presence of tolerance against C. partellus.