author(s)
Dalip Kumar, Dilbag Singh Ahlawat, Lomash Kumar, Deepika Kalkal and Vivek Kumar Saini

abstract
Sugarcane genotypes selected on the basis of dead hearts formation were studied for biochemical based characters of resistance. Variations in biochemical parameters were recorded especially amount of total and reducing sugars at 45 days after planting (DAP), the least susceptible genotypes contained less, whereas highly susceptible group had more total and reducing sugars. The highest amount of total sugar was estimated in highly susceptible variety CoJ 64 (7.9%) and lowest in genotypes Co 87263 (4.9%). At 60 DAP; highly susceptible genotypes recorded the highest total and reducing sugar contents; average content of total sugars were 5.1, 5.7 and 7.2 per cent and of reducing sugars 0.06, 0.094 and 0.192 per cent in least moderately and highly susceptible entries. Tannin contents at 45 DAP decreased gradually with the borer susceptibility. The average tannin content of least, moderately and highly susceptible entries were estimated to be 12.06 mg, 11.71 mg and 10.22 mg per gm dry weight of tissue, respectively. Highly susceptible genotypes recorded highest average nitrogen content (1.6%) as against least (1.35%) and moderately susceptible (1.42%). Phosphorus contents accounted with an average content of 0.39 per cent in least susceptible, 0.36 per cent in moderately susceptible and 0.3 per cent in highly susceptible genotypes. Lowest average potassium content (1.67%) was evident in highly susceptible entries in comparison with least and moderately susceptible, which recorded 2.4 and 2.2 per cent potassium contents, respectively. Highly significant positive association of nitrogen level and highly significant negative correlation of potassium and phosphorus levels with varietal susceptibility have been observed.