Effects of fruit number on yield, fruit weight and soluble solids of peach

Fruit thinning treatments elicited a wide range of crop loads (fruit number tree(-1), FN) at harvest (80<FN<480) in irrigated peaches grown in the Goulburn Valley of SE Australia. Responses to FN suggested that yield was sink-limited in the range of FN, FN<250, whereas there was little further increase with FN in the range, FN>250. Fruit size and soluble solids decreased with increased FN: yield, fruit size and soluble solids consequently appeared to be source-limited under large FN. Low FN was predominantly associated with low yields of large sweet fruit. Findings suggested that large fruit size and sweetness may be combined with high yields by thinning strategies that seek to balance source and sink limitations in the tree.