The object of this study was to find the optimum time of harvesting and dose of potash for sugarcane crop in various states of the country by using suitable response surface model. In most of the cases optimum times of harvesting and doses of Potash were calculated by using Quadratic response surface model for Sugarcane crop. In Andhra Pradesh optimum level of harvesting time was observed 12.96 months after planting at optimum level of 119.7 kg/ha. of K2O and yield was 1106.87 q/ha. in Bihar, optimum level of harvesting time was observed 11.04 months after planting at optimum level of 175.89 kg/ha. of K2O and yield was 1407.90 q/ha. in Karnataka, optimum level of harvesting time was observed 16 months after planting at optimum level of 151.9 Kg/ha. of K2O and yield was 1666.83 q/ha. in Uttar Pradesh, optimum level of harvesting time was observed 14 months after planting at optimum level of 177.5 Kg/ha. of K2O and yield was 692.45 q/ha. In most of the states early harvesting and late harvesting of sugarcane were not beneficial for maximum yield.
