Studies on the Thinning of the Fruits By Hand and with Plant Growth Substances and Their Effects on the Final Retention and Quality of Apple Cv. Red Delicious

All the concentrations of Alar, Carbaryl and Ethrel induced maximum thinning, while NAA 10 ppm and 2,4,5-T 10 ppm had the minimum thinning effect. The higher doses of NAA and 2,4,5-T (50 ppm) and hand thinning (50 per cent) were also quite effective in the thinning of fruits. Significant reduction in the size was also observed by Alar treatments, which though gave maximum pressure values. The treatments with growth substances and 50 per cent hand thinning increased the T. S. S. and total sugar contents of the fruits. The ascorbic acid content was increased by 2,4,5-T and NAA 10 ppm, Alar 1500 ppm and Ethrel 500 ppm.