Effect of polyhalite and muriate of potash on quality attributes of sugarcane (Saccharum officinarum L.) in Inceptisols

Polyhalite is a hydrated sulphate evaporate mineral containing potassium, sulphur, calcium and magnesium that crops require in significant quantities but has limited evaluation as a fertilizer for sugarcane.The sugarcane crop has a high demand for potassium for better quality. To keep the above facts in mind, the present experiment was conducted to evaluate the effect of polyhalite and muriate of potash (MOP) on the quality attributes of sugarcane var. Co 11015 (Atulya) in sandy loam soil at Arachalur, Erode district. The experiment was laid out in a randomized block design consisting of ten treatments. The treatment included were T1 –control, T2 - 50% K as MOP, T3 - 100% K as MOP, T4 - 100% K as Polyhalite, T5 - 100% K (1:1 ratio of Polyhalite and MOP), T6 - 100% K (1:3 ratio of Polyhalite and MOP), T7 - 150% K as MOP, T8 - 150% K as Polyhalite, T9 - 150% K (1:1 ratio of Polyhalite and MOP), T10 - 150% K (1:3 ratio of Polyhalite and MOP). The application of potassium fertilizers in different levels and ratios significantly (5%) influenced the quality attributes of sugarcane. The results of the experiment revealed that the application of 150% K (169.5 kg K2O ha-1) as polyhalite (T8) recorded maximum brix, pol, purity, CCS%, and extraction% and also this treatment was recorded minimum reducing sugar and fibre%. The present experiment would be helpful to sugarcane farmers for quality improvement through the application of polyhalite as a potassium fertilizer.