Effect of plant bio-regulators and urea on growth of walnut seedling under Kashmir condition

Abstract

The experiment was carried out by adopting double split plot design with eighteen treatments replicated thrice. The treatments combinations consisted of foliar sprays of gibberellic acid (GA3) and Indole-3-Butyric Acid (IBA) each at 200 and 400 ppm and urea at 0.3% alone or in combinations. Of the tested treatment combinations, application of 400 GA3 + 200 ppm IBA + 0.3% urea resulted the highest growth of walnut seedlings in respect of seedling height (66.33 cm), number of leaves per seedling (70.67), leaf area (63.27 cm2) and stem diameter (17.18 mm) whereas, the longest tap root ( 52.73 cm) and highest number of secondary roots (33.20) were noticed the plants, sprayed with 200 ppm GA3 + 200 ppm IBA + 0.3% urea. The maximum percentage of graftable size seedlings (100%) attaining diameter of 10 - 15 mm was obtained in the treatment comprising of GA3 @ 0 ppm + 200 ppm IBA + 0.3% urea, however application of 400 ppm GA3 + 200 ppm IBA + 0.3% urea registered 86.7% graftable size seedlings, having a diameter more than 15 mm. Minimum sturdiness quotient of 3.66 was recorded with 400 ppm GA3 + 200 ppm IBA + 0.3% urea. Based on the results, it can be concluded that four foliar applications of 400 ppm GA3 + 200 ppm IBA + 0.3% urea on walnut seedlings at an interval of 21 days, starting from 3-4 leaf stage, significantly increased the overall growth of walnut seedlings and thus, led to the production of more number of graftable size plants with in a year.