Asian Journal of Soil Science and Plant Nutrition

The production and demand for onion are relatively high. India has occupied the second position with 5.5 lakh hectares of area under onion cultivation with 77 lakh tonnes of production next to China in the world. Tamil Nadu is the major small onion producer for nearly 70 percent of total area in India. This work aimed to studying the effect of plant growth regulators and nutrient mixtures on growth, physiology and biochemical changes and yield of small onion. A field experiment has been taken at Horticultural College and Research Institute for women, Trichy during Oct 2023 to study the influence of plant growth regulators and nutrient mixture on maximizing the growth and yield of onion. The treatment includes control, foliar spray of Brassinolide 1.0ppm, Salicylic acid 100ppm, GA3 100ppm, NAA 100 ppm and combination of K₂SO4 (1 %)  + CuSO₄ (0.5 %) + ZnSO₄ (0.5 %) by using RBD with four replication. Two foliar sprays of growth regulators and nutrient mixture has been given on 25 and 45 DAP. The growth characters Viz., Plant height (31.93 cm) and No. of leaves (20) were highest in Brassinolide 1ppm treated plants at 60 Days After Planting. The root length was significantly varied among the treatments. Among the treatments Salicylic acid 100 ppm recorded the maximum root length of (10.06 cm). The quality attributes of the bulbs include total Soluble solids (12.18%), Pyruvic acid content (2.57 µmolg^-1) were found with the foliar spray of Brassinolide 1ppm. Among the treatments highest bulb yield was recorded by Brassinolide 1ppm. The yield increase was 12 % compared to control followed by Salicylic acid 100ppm recorded the highest yield.