Harvest maturity standards and fruit quality of some apple cultivars under high altitudal conditions

Abstract

The maturity standards and fruit quality of apple cultivars, viz., Vance Delicious, Starkimson, Red Chief, Oregon Spur, Gala Must, Royal Delicious, Red Delicious and Golden Delicious were assessed during 2007-2008 at Mukteshwar (Uttarakhand) situated at 2,250 m amsl. The studies revealed that full bloom duration of different cultivars varied during both the years but the varietal sequence of flowering was the same. Among the cultivars Vance Delicious came into bloom early in both the years. The estimated harvesting date for sampling of each cultivar was determined on the basis of fruit size, weight, TSS, acidity, back ground skin colour and ease of fruit separation from spur. The various cultivars were found to mature when the average starch iodine score reached 4.83 to 5.67. Furthermore, red coloured cultivars attained maturity when the skin colour developed between 50 to >75%. Similarly the skin colour of Golden Delicious cultivar turned into yellowish-green on maturity. All the fruit physical parameters and TSS increased significantly from first to fifth sampling in all the cultivars. Accordingly fruit acidity showed a declining trend from 2.53% in Gala Must to 0.38% in Royal Delicious. The mean days after full bloom to harvest at IV sampling stage varied from 110.0 (Vance Delicious) to 145.5 (Golden Delicious). In the range of 68.0% (Red Delicious) to 74% (Vance Delicious) fruits were harvested with ease of separation at IV sampling stage and this stage was found to be suitable for harvesting of fruits on optimum maturity.