Foliar Application of Potassium Salt of Active Phosphorus (PSAP) Mitigates Insect Pests and Improves Yield Along With Sugarcane Quality in Response to Agroclimatic Conditions of Punjab

In semiarid tropics, potassium (K) and phosphorus (P) are the major nutrients that enhance the yield and juice quality of the sugarcane plants. The research experiment was carried out at PAU-Regional Research Station, Kapurthala, Punjab, India, on the potential of Potash Salt of Active Phosphorus (PSAP) which contains potassium and phosphorus during the spring season of 2021-2022 concerning insect-pests, yields, and quality parameters. With 50% reduction of P and K fertilizers, treatments compared with control (T-1, treatment frequency @3 times, water spray) with different foliar sprays of PSAP concentrations, such as 12.5, 15.0, and 25 kg ha(-1) at 60, 90, and 120 days after planting as T-2, T-3, and T-4, respectively. Relative to the control plots, 12.5, 15, and 25 kg ha(-1) PSAP treatments had significantly higher cane length, diameter, millable canes, yields and sugar recovery (%), which were 2.17, 2.26 and 2.30%; 1.83, 1.47 and 1.47%; 7.69, 8.97 and 9.23%; 12.51, 12.72 and 12.72%; 20.4, 18.6 and 17.8%, respectively. Further, the incidence of early shoot borer (Chilo infuscatellus), top borer (Scirpophaga excerptalis), and stalk borer (Chilo auricilius) was reported to be significantly lower during T-2, T-3 and T-4 to the tune of - 31.3, - 25.0 and - 18.7%; - 27.8, - 19.4 and - 16.7% and - 27.6, - 24.2 and - 20.7%, respectively, as compared to the control (T-1) plots. Better growth, yield, and quality parameters along with lesser insect-pest incidence resulted in higher B: C ratio of 1.40 in T-2 treatment as compared to 1.19 and 0.71 in T-3 and T-4 as compared to T-1 treatment. Our results suggest that PSAP @12.5 kg ha(-1) may be recommended for reducing insect incidence and for enhancing sugarcane growth, yield, and sugar recovery.