Effect of plant bio-regulators on photosynthesis, growth and yield efficiency of pear trained on Y-trellis system

‘Patharnakh’ and ‘Punjab Beauty’ are major pear cultivars grown under the subtropical conditions of northwestern India. These tend to put up profuse vegetative growth high density planting that leads excessive shading bearing zone canopy. To facilitate light penetration into inner plant canopy, there is a need contrive an efficient approach for management. The foliar applications varying concentrations bio-regulators viz. Prohexadione calcium (Pro-Ca) (100, 200, 400 mg L-1) Paclobutrazol (PBZ) 250, 500 were done at 10 days after full bloom (DAFB) plants trained on Y-trellis training system. Shoot length, leaf area index trunk cross-sectional areas (TCSA) greatly reduced by Pro-Ca200 L-1 concentrations. Treatments enhanced photosynthesis. Fruit weight improved with bio-regulator treatments resulting in increased yield efficiency plants. This study exhibited strong positive correlation between availability