Effect of plant growth regulators on growth, yield and quality attributes of watermelon (Citrullus lanatus Thunb.)

Plant growth regulators are called as magic chemicals which are new generation agrochemicals. Exogenous application of plant growth regulators in small quantity can alter the sequence of male and female flowers, if applied at 2 or 4 leaf stages, the critical stage at which the suppression or promotion of either sex is possible. Therefore, a field experiment was carried out during Rabi, 2021 at Horticulture Research Farm, M.S. Swaminathan School of Agriculture, Centurion University of Technology and Management, Parlakhemundi, Odisha to study the influence of plant growth regulators on growth, yield and quality attributes of watermelon. The experiment was laid out under randomized block design with nine treatments namely 2, 4-D (25 and 50 ppm), NAA (100 and 150 ppm), GA₃ (30 and 40 ppm), TIBA (20 and 25 ppm) and control (distilled water)replicated thrice. Two sprays of plant growth regulators were done at 2^nd and 4^th true leaf stages. The results revealed that growth characters such as length of the main creeper (2.08 m), number of sub creepers per plant (4.40) and chlorophyll content (61.93 and 48.91 at 30 and 60 DAS) were highest in treatment (GA₃ @ 40 ppm). The chlorophyll content at 90 DAS was highest (21.39) in treatment (NAA @ 100 ppm). The highest fruit yield plant⁻¹ (17.51 kg) and fruit yield per hectare⁻¹ (44.17 t) was recorded in treatment (GA₃ @ 40 ppm). The quality attributes such as Total Soluble Solid (TSS) (10.66%) and total sugars (15.03%) were noted highest in treatment (GA₃ @ 40 ppm). Among the different plant growth regulators spraying of GA₃ @ 40 ppm found effective in enhancing the growth, yield and quality attributes of watermelon.