Effects of ethrel and naphthaleneacetic acid on fruit quality and fruit drop of ‘Royal Delicious’ apple

In both the years (1999 and 2000) the application of ethrel 300 ppm greatly increased the colour of the fruit. Ethrel 300 ppm also tended to show the marked increase in the contents of TSS and sugars but lowered the acidity of the fruit. In general, for the colour development, sugar acid blend taste and to check fruit drop, the use of ethrel 300 ppm + NAA 10 ppm proved to be effective.