Thinning of cling peaches with ethephon in the Riverland area of South Australia

Abstract

An ethephon spray 39 to 53 days after full bloom effectively thinned both Golden Queen and Wight peaches in 1973 and 1974, and Wight and Keimos cultivars in 1975, but gave inconsistent results in commercial demonstrations in 1976. The optimum concentration was 40-100 ppm and depended on the degree of thinning needed. Concentrations in this range did not cause any leaf fall but increased the amount of gumming and stone splitting in Golden Queen fruit in 1974; there were no other detrimental effects on the fruit. Uneven thinning between and within trees of Keimos was a problem in 1975.