Potential of plant-growth regulators and nutrients sprays on yield and yield components in lucerne (Medicago sativa)

Abstract

An experiment was conducted at the Punjab Agricultural University, Ludhiana, during the winter (rabi) seasons of 2017–18 and 2018–19, to evaluate the effects of different plant-growth regulators and nutrients applied as foliar sprays on yield and yield components of lucerne (Medicago sativa L.). The treatments comprised foliar applications of 0.25% ZnSO4 , 1.0% K2 SO4 , 1.0% (monoammonium phosphate) MAP, 100 ppm salicylic acid, 500 ppm mepiquat chloride and 1.0 ppm brassinolide at pre-flowering stage and 10 days after the first spray along with the control. Plant-growth regulators and nutrient sprays significantly increased the seed yield of lucerne over control by 22.4 to 31.0% in 2017–18 and by 5.5 to 17.8% in 2018–19. The highest seed yield of 122.4 and 167.5 kg/ha in 2017–18 and 2018–19 respectively, was obtained with application of 1.0 ppm brassinolide. The significant increase in yield was obtained mainly owing to increase in number of pods/plant and number of seeds/pod. None of the foliar applications showed any effect on lucerne seed quality, i.e. 1,000-seed weight and seed germination. The monetary returns were also significantly higher with 1.0 ppm brassinolide application. Hence, plant-growth regulators may be used to enhance lucerne seed production while maintaining its seed quality.