SINGH, V. P.Y. C. VISHWANATHS. M. PRASANNAVIJAYMAHANTESHJHALEGAR, MD. JAMEELD. P. MANJU PRASADA2023-10-062023-10-062021UHS18PGM1065https://krishikosh.egranth.ac.in/handle/1/5810198530An experiment entitled “Role of growth regulators on growth, yield and quality of Alfalfa (Medicago sativa L.) under Northern dry Zone of Karnataka” was conducted during rabi season, at department of Plantation, Spices, Medicinal and Aromatics Crops, College of Horticulture, UHS, Bagalkote, Karnataka, during the year 2019-20. In this experiment, the plant growth regulators viz., GA3 (50 ppm and100 ppm), IAA (50 ppm and 100 ppm), NAA (50 ppm and100 ppm), Kinetin (50 ppm and 100 ppm), Humic acid (4.0ml/l and 6.0ml/l), Salicylic acid (1.5 g/l and 3 g/l) and water as control were sprayed at 30, 60, 90 and 120 days after sowing and analysed for their vegetative growth, yield and quality parameters. Among different growth regulators, the plants sprayed with GA3 at 100 ppm recorded highest plant height (79.48 cm, 75.83 cm, 74.67 cm and 71.50 cm), stem diameter (5.09 mm, 4.54 mm, 3.68 mm and 3.26 mm) and leaf area (811.81 cm2 , 976.02 cm2 , 740.65 cm2 and 557.21 cm2 ) at I, II, III and IV harvest i.e., on 50, 80, 110, and 140 DAS, respectively. However, the plants sprayed with Kinetin at 50 ppm persistently recorded maximum plant spread (22.57 cm, 30.60 cm, 20.17 cm and 16.77 cm) at I, II, III and IV harvest respectively. During I, II, III and IV harvest, the plants sprayed with GA3 at 100 ppm recorded significantly maximum fresh herbage yield per hectare (16.59, 17.73, 13.43 and 11.12 t/ ha respectively) and dry herbage yield per hectare (4.01, 4.15, 3.70 and 3.42 t/ha respectively). The quality parameters of alfalfa were significantly influenced by different plant growth regulators. The highest protein content (17.65%) and vitamin C (276.73 mg/100g) content was observed in the plants sprayed with GA3 at 50 ppm. Plants sprayed with humic acid at 4.0ml/l recorded a significantly higher vitamin B12 (1.19 ng/g). Overall, application of plant growth regulators at different concentration plays an important role in alfalfa growth, yield and quality. All the applied growth regulators increase growth and yield as compared to control. Among different growth regulator and its concentrations, the plants sprayed with GA3 at 100 ppm showed better result for growth and yield which was followed by kinetin at 50 ppm. Regarding quality parameter, vitamin C and protein content found highest in plants sprayed with GA3 at 50 ppm, while vitamin B12 was found highest in plants sprayed with humic acid at 4 ml/l.EnglishThesis