study on the effects of summer pruning and calcium phosphat on color improvement and other qualitative characterize of red delicious apple after storage in semirom

a study of two years was carried out on apples, red delicious cv. in comeh of semirom region. the objective of this research was to assess the effect of pre-harvest calcium phosphate (seniphos) spraying and summer pruning on the skin color and quality characteristics of the fruit. study was carried out using a complete randomized block design with 3 replications. trees were subjected to pre-harvest spraying of 0.8, 1% and 1.2% seniphos (calcium phosphate) and pruning on 6 and 21 of august. a control test also was carried out. each block contained 3 trees. 15 kilo of fruit was harvested randomly from each block. firmness, skin color, acidity, tss, overall acceptability, bitter rot, rotting and farinaceous texture of fruit were assessed after 2 and 4 month storage at 4 ºc and 95% of humidity. anova test based on 2 year study data indicated significant effect of applied treatments (α=1%) on all studied parameters. skin redness increased significantly comparing to the control sample. the highest redness was observed in the 1.2% seniphos spraying treatment. after 2 months of storage, firmness farinaceous texture, bitter rot and overall acceptability of fruit in seniphos and summer pruning treatments changed significantly comparing to those of control sample. after 4 months of storage, there was significant difference between 1.2% seniphos treatment and other treatments including the control in view point of firmness, rotting, farinaceous texture and bitter rot of the fruit. the acceptable firmness and overall acceptability were obtained by using 1% and 1.2% seniphos spraying treatments.