Studies on crop regulation with chemical thinning, gibberellic acid and pruning in nectarine cv. May Fire
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
YSPU
Abstract
The present investigations entitled “Studies on crop regulation with chemical thinning, gibberellic acid and pruning in nectarine cv. May Fire” were carried out on 12-year-old trees of nectarine cultivar May Fire raised on wild peach seedling rootstocks at the experimental orchard of Horticulture Research Station, Kandaghat, District Solan and Farmer’s orchard at Kotla Barog, District Sirmaur during 2014-15. In experiment I, experimental trees were subjected to nine treatments viz. NAA at 40 ppm and 60 ppm; Ethrel at 200 and 300 ppm applied one and two weeks after petal fall and control with three replications in Randomized Block Design. At both locations, treatment with NAA at 40 ppm when applied two weeks after petal fall induced significantly higher thinning, increased shoot growth, tree height and spread, leaf area, photosynthetic rate, chlorophyll content, leaf to fruit ratio, superior grades’ fruit yield, fruit size, weight and volume. Total soluble solids, total sugar and reducing sugar contents were higher and acidity and firmness lower in the fruits from trees treated with NAA at 60 ppm two weeks after petal fall during both the years, irrespective of locations. Surface colouration was higher in fruits from trees treated with Ethrel at 300 ppm two weeks after petal fall during both the years, irrespective of locations. However, chemical thinners were more effective at Kandaghat, in respect of all these parameters and the induction of fruit abscission following application of treatments was higher during 2014 compared to 2015 over the control. In different NAA and Ethrel treatments, disintegration of cells in pith, vascular and cortex regions was advanced at Kandaghat in the year 2014 at 20.5- 24.5°C/ 13-14°C maximum and minimum temperature and 47.3-60.3% average relative humidity after application chemical thinners. In experiment II, experimental trees were subjected to 17 different treatments of crop regulation with chemical thinners, pruning and GA 3 ; chemical thinner were more effective in improving the production of superior grade fruits than reducing the crop load directly by pruning or indirectly by GA treatments.Again treatments with NAA at 40 ppm when applied two weeks after petal fall reduced the crop load to the greatest extent and improved fruit size, yield of superior grade fruits and fruit quality. Pruning to retain 40 fruiting shootstree-1+ NAA 40 ppm, 2WAPF increased the shoot growth, tree height, tree spread and leaf area.
Description
Keywords
fruits, biological phenomena, pruning, auxins, plant growth substances, developmental stages, peaches, biological development, yields, acidity