Effect of foliar application of zinc sulphate and plant growth regulators on quality and leaf nutrient status of guava (Psidium guajava L.) cv. Hisar Surkha

A field study was carried out at the Experimental Orchard, Department of Horticulture, CCS Haryana Agricultural University, Hisar (Haryana) on six year-old guava trees cv. Hisar Surkha to determine the effect of foliar application of zinc sulphate and plant growth regulators on the quality and leaf nutrient status of guava. Different treatments were taken i.e. T1 : ZnSO4.7H2O @ 0.25%, T2 : ZnSO4.7H2O @ 0.50%, T3 : ZnSO4.7H2O @ 0.75%, T4 : ZnSO4.7H2O @ 1.0%, T5 : NAA @ 25 ppm, T6 : NAA @ 50 ppm, T7 : NAA @ 75 ppm, T8 : NAA @ 100 ppm, T9 : GA3 @ 50 ppm, T10 : GA3 @ 75 ppm, T11 : GA3 @ 100 ppm and T12: Control (water spray) with three replications under randomized block design. The results of the study revealed a significant increase in the quality and leaf nutrient status of guava fruit. However, foliar application of NAA @ 100 ppm proved to be the best treatment in improving the TSS (12.93oB), TSS/Acid Ratio (39.18), total sugars (6.75 %), reducing sugars (4.05 %) and non-reducing sugars (2.70 %) and foliar application of GA3 @ 100 ppm improved the pectin content (0.89 %), ascorbic acid content (208.4 mg/100 g pulp) and leaf nutrient status of guava fruit over control.