Studies of fruit shape in apples: response to gibberellin and cytokin sprays

Abstract

Results of experiments over two seasons at two locations in New South Wales and one in Western Australia have shown that 'typiness' of Red Delicious apples can be improved by the use of blossom applications of the plant growth regulators gibberellin (GA4/7) and N6benzyladenine (BA). Benzyladenine was the more effective of the two materials tested, and stimulated both an increase in the length : diameter ratio (L/D) of the fruit and development of the calyx lobes. The gibberellins were less consistent in their effect. Sprays combining both GA,/, and BA in equal proportions provided little additional benefit to that obtained with BA alone at the equivalent strength.