Effects of water rinses after calcium chloride dips, with and without additives, on the control of bitter pit of apples

Abstract

Studies on the control of bitter pit in apples after harvest were conducted during two seasons in Tasmania and New Zealand. The cultivars, Cox's Orange Pippin, Sturmer Pippin, Golden Delicious, Delicious and Cleopatra, which are susceptible to bitter pit on overseas markets, were examined. Bitter pit was reduced and calcium content of the fruit increased, by dipping the fruit in calcium chloride solutions (1-3% w/v). The addition of diphenylamine or the non-ionic wetting agent, Agral 60 (ICI Australia), had little effect on the control of bitter pit or on the calcium content of the treated fruit. Rinsing in water even 1 or 2 days after dipping did not significantly increase the incidence of bitter pit or lower the calcium content of the fruit. There was no difference in the incidence of bitter pit between fruit stored at ambient temperature (15-20¦C) or at 3-5¦C during the interval between dipping and rinsing. Dipping apples in calcium chloride followed, after 1 or more days, by a water rinse may be suitable commercially for reducing bitter pit in a number of cultivars.