Factors affecting fruit damage to mechanically harvested peaches in Goulburn Valley orchards

Abstract

To determine whether Goulburn Valley peach trees need modification to reduce damage to fruit that are harvested mechanically, the effect of fruit and tree characteristics on damage to fruit were investigated. Relationships were established between measurements of the structural characteristics of the tree frame and fruit damage. Fruit damage levels were lower for trees with fewer scaffold limbs that subdivide at higher levels but without secondary branches beneath them. Damage levels increased with tree size and larger fruit. For limbs without secondary branches beneath them, the percentage cut fruit was lower for fruit originating from below 2 m of tree height. The percentage of cut fruit was shown to be significantly lower for fruit with an unobstructed fall. For the cultivar Golden Queen, which had the fruit bearing wood close to the limbs, shaking caused sufficient deflection, before or after detachment of the fruit, to strike adjacent or lower wood, resulting in cuts. However, for the cultivar Tatura Dawn, which was pruned to produce fruit on hangers, there was no evidence that shaking caused deflection of fruit. Bruising was shown to be a function of fruit firmness for both hand and machine harvested fruit. For selected trees with five to seven scaffold limbs and a large proportion of fruit with a free fall, fruit damage levels compared favourably with hand picked fruit.