Effect of exogenous application of plant growth regulators on vine growth, yield and quality attributes in kiwifruit cv. Hayward

Present investigation was carried out on 11-year-old vines of kiwifruit cv. Hayward trained on a T bar trellissystem for two years. Four different plant growth regulators viz., GA₃ (25 & 50 mg l⁻¹), BA (10 & 20 mg l⁻¹), 2, 4-D (10 & 25 mg l⁻¹), TRIA (10 & 20 mg l⁻¹) and a natural extract (4 g ml⁻¹) were sprayed four weeks after full bloom. Allthe growth regulators proved effective in improving vine growth, yield and physico-chemical characteristics offruits as compared to control. Maximum shoot growth (157.27 & 153.49 cm) was observed with the applicationof 50 mg l⁻¹ GA₃. Maximum leaf area (190.25 & 188.34 cm²) was obtained with 25 mg l⁻¹ of GA₃. The highest fruitretention (86.19 & 81.06%) and yield per vine (57.98 & 54.82 kg) was recorded with 10 mg l⁻¹ 2, 4-D. Advancement in harvest maturity was noted with 10 mg l⁻¹ TRIA. Among all the treatments, application of 25 mg l⁻¹ GA₃ followed by 10 mg l⁻¹ 2, 4-D proved to be more effective in improving fruit physical characteristics viz., fruit weight, fruit length & fruit diameter; and chemical characteristics viz., total soluble solids and total sugars.