Evaluation of sugarcane germplasm against early shoot borer (ESB), Chilo infuscatellus snellen

Field evaluation of 147 genotypes/varieties was taken up at Agricultural Research Station, Basanthpur, Medak district, A.P, India against early shoot borer, Chilo infuscatellus Snellen, of which 12 genotypes have shown low to high susceptibility and were graded along with one susceptible check, 93 A 145,and further screened for their reaction to ESB. The genotypes Co 0110 (8.49%), 98 A 165 (9.85%), Co6806 (9.57%) and 98 A 125 (8.01%) were least susceptible (LS); genotypes 97 A 85 (22.48%), 2000 A 105 (24.28%), 99 A 5 (24.23%) and C062175 (26.31%) were moderately susceptible (MS) whereas genotypes 93A 11 (31.85%), 99 A 33 (37.53%), 94 A 124 (34.98%) and Co M 9902 (41.82%) were highly susceptible (HS) with susceptible check, 93 A 145 recording 39.24% incidence of ESB.These thirteen genotypes were evaluated for mechanisms of resistance to ESB and for Bio-physical and biochemical studies.Parameters like thickness of leaf sheath, hieght and girth of the plant, number of leaves, Leaf inclination erectness,/droopiness, length and width of leaf were recorded and there was no correlation between physical parameters with the intensity or incidence of stalk borer. Intensity of stalk borer was positively correlated with the incidence of stalk borer. Biochemical differences were studied by collecting plant samples in the field at 60 DAT to estimate moisture content, total phenols, total sugars, reducing sugars, chlorophyll, nitrogen, phosphorus, potassium, protein content in shoot and leaf sheath tissues and Neutral detergent fibre (NDF), Acid detergent fibre (ADF), cellulose, lignin and silica contents in shoot tissues. The LS genotypes, contained relatively higher amount of cellulose, lignin and silica, the basic constituents of NDF and ADF that had a supportive function in cell wall thickening and hardening of plant tissues, thereby, helping avoid attack by the ESB, C. infuscatellus.