Assessing the Influence of Potassium Fertilizer Variations on Growth, Yield, and Crop Quality of Sugarcane (Saccharum officinarum L.) Genotypes

Potassium is a key plant nutrient that is required in huge quantities by sugarcane. Potassium is an activator of many enzymes of growth and sucrose synthesis in sugarcane. Potassium, a critical macronutrient, significantly influences the physiological and biochemical processes in sugarcane, affecting root development, stalk elongation, and sucrose accumulation. The identification of sugarcane genotype's responsiveness with respect to specific dose of potassium fertilizer was prime objective of the study. So, the present study was planned to examine the impact of varying doses of potassium fertilizer on growth, yield and quality of different sugarcane genotypes for two consecutive years 2018-19 and 2019-20. There were three sugarcane genotypes i.e. Raja-14, Q-88, and PS-TJ-41, and four concentrations of potassium i.e. 0 kg K2O, 100 kg K2O, 150 kg K2O, and 200 kg K2O per hectare were applied. Randomized complete block design with split plot arrangement was selected having three replications per treatment. The sugarcane genotypes were placed in the main plots while potassium doses were sited in sub plots. This study revealed that sugarcane growth, yield and quality are significantly affected either by sugarcane genotype, potassium application rate and their interactive effect. In our study, PS-TJ-41 variety outperformed the Q-88 and Raja-14 in all growth, yield and juice quality parameters except sprouting capacity, Cane length and intermodal distance. Maximum sprouting (76.33%) was observed in Q-88 with 150 kg K2O application. However, maximum cane girth (2.82 cm), 10 cane weight (15.17 kg) was noted in PS-TJ-41 with 150 kg K2O application. Furthermore, PS-TJ-41 yielded the highest performance (128.83 tons/ha) in response to 150 kg K2O application, an indication that selecting the right sugarcane genotype and utilizing optimal potassium fertilization rate is key to enhancing sugarcane yield. Similar trend was observed in quality parameters where maximum Brix (22.50%), Pol (19.80%), Purity (86.50%) and sugar recovery (13.75%) was recorded in PS-TJ-41 with 150 kg K2O application. All three sugarcane genotypes obtained highest yields at 150 kg K2O fertilizer application rates. The selection of the most productive sugarcane genotype and applying optimal potassium fertilizer rates can enhance sugarcane productivity and yield.