Dr. SHASHIDHAR. T. R.SHASHI KUMAR H. M.2018-12-262018-12-262015-07http://krishikosh.egranth.ac.in/handle/1/5810086294Field experiments were conducted to find out the effect of plant growth regulators and bio stimulants in the production of onion during Rabi 2014 and 2015 at the Main Agricultural Research Station, University of Agricultural Sciences, Dharwad. The experiment was laid out in Randomised Complete Block Design with twelve treatments replicated thrice. Maximum plant height (64.30 cm) was recorded from the plots sprayed with GA3 @ 60 ppm whereas the higher number of leaves (10.63) and higher leaf area (1204.49 cm2/plant) were noticed in the plot sprayed with lihocin @ 2500 ppm. Significantly higher neck thickness (18.64 mm) and higher dry matter content (16.9 gm/plant) were noticed in the treatment lihocin @ 2500 ppm. Significantly higher yield (54.0 t/ha) was noticed from the plots sprayed with lihocin @ 2500 ppm and the minimum yield (41.2 t/ha) was noticed in the control plot. The higher average weight of the bulb (119.60 g/bulb) and marketable yield of the bulbs (51.60t/ha) were recorded from the plots sprayed with lihocin @ 2500 ppm. Total Soluble Solids varied significantly at harvest and the higher TSS was noticed in the treatment NAA @ 300 ppm (13.7). The higher cost benefit ratio (7.13:1) was recorded in the treatment lihocin @ 2500 ppm. The pre harvest application of lihocin @ 2500 ppm recorded the lower physiological loss in weight (18.5%), higher drymatter content (15.10%) and higher percentage of marketable bulbs (79.5%) during the course of storage. Significantly lower percent loss in scale was noticed in the treatment NAA @ 300 ppm (26.75%). Among all the treatment lihocin @ 2500 ppm was the best for getting higher yield and good storability of onion bulbs.ennullThesis