The effect of pre-harvest calcium chloride application on the harvesting quality and storage duration and ethrel induced ripening of Sceptar red raspberry

Raspberries of the cultival Sceptar were sprayed four times before harvest with different levels calcium chloride (0.1, 0.2, 0.4, 0.8, 1 and 2/). The harvest fruit were separated into three distinct maturity stages: red, deep red and dark deep red. Untreated or CaCl2 treated raspberry fruit were harvested at the red maturity stage and stored at 0oC and 80-85/RH. Fruit calcium content, fresh weight, firmness, soluble solids content, juice pH, tritable acidity, anthocyanin and ascorbic acid content were measured at harvest or during storage. CaCl2 sprays increased calcium content, berry weight, firmness andanthocyanin content; SSC decreased, while pH, tritatable acidity and ascirbic acid were not affected. 0,8 treatment was more effective on weight and firmness. Spray with 1 CaCl2 resulted in wilted burnt leaves, retarded cane growth and damaged the fruit after the fourth application. During storage at 0oC fresh weight, firmness and ascorbic acid generally decreased, with the highest rates of decreases detected in untreated fruit and fruit treated with 1 CaCl2. The pH, SSC and anthocyanin content increased during storage, berries treated with 0.2,0.4 and 0.8 CaCl2 were less affected by storage and maintained their quality characteristics during the latter better. Raspberries at 3/4 red maturity stage were harvested, part of them were trated with ethrel and the others were left as control. Both were stored at 0,11 and 20oC. During storage, fresh weight, firmness, SSC, itratable acidity and anthocyanin were measured. For both untreated and ethrel treated berries fresh weight, firmness and titratable acidity decreased, while SSC, ph and anthocyanin content increased during storage, with different rates of decrease or increase in all the berries at each temperature.