Influence of various biochemical factors on the occurrence of Helicoverpa armigera (Hubner) in Tomato

Experiment on the influence of various biochemical factors on the occurrence of Helicoverpa armigera in tomato was carried out under field conditions, following RCBD on fourteen commercially available tomato genotypes viz. Mission 102, Sultan, 027, Chinar, GS 5575, Sourabh, T 7008, R 165, RK 101, Riogrande, Roma, Bambino, Super Classic and Roma VF. Results indicated that genotype chinar was found to be the most resistant while genotype R 165 was found to be most susceptible. Chemical analysis revealed ascorbic acid, phenols and acidity showed negative correlation with fruit infestation, while ash and pH showed positive correlation. Moisture had non significant negative correlation with both larval population and fruit infestation. Multiple linear regression models showed resistance to be influenced by combination of various factors rather than a single factor. Tomato genotypes with high content of both ascorbic acid and phenols, as well as acidy could be used as marker traits for resistance against H. armigera.