The effect of Alar on vegetative growth and fruiting behaviour of three varieties of apples in the Central Tablelands of New South Wales

Abstract

Trials were conducted in three successive years to test the response of Granny Smith, Jonathan, and Delicious apple varieties to Alar (succinic acid 2, 2-dimethyl hydrazide) applied at various times and concentrations. The results confirmed overseas reports of reduced shoot growth, increased fruit set, reduced fruit size, reduced pre-harvest drop, and, in some cases, increased blossoming the following spring. The Jonathan variety was less responsive to the growth retardant than Delicious, which was, in turn, less responsive than Granny Smith.