KIWIFRUIT YIELD EFFICIENCY, PLANT-DENSITY, AND BUD NUMBER PER SURFACE UNIT

Kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] crop response to variations in plant density and bud number per surface unit of growing area was studied to determine optimum levels of these factors. Five bud numbers per surface unit (50,000, 100,000, 150,000; 200,000, and 250,000 mixed buds/ha) and four plant densities, obtained by varying the in-row spacings (1.5, 3.0, 4.5, and 6.0 m), were combined in a factorial design and tested in a kiwifruit orchard during two growing seasons on the same vines. Kiwifruit yield increased from 7 to 24 t•ha —1 with increasing bud number per hectare according to a 2nd-order polynomial function. Both the reduction in the mean fruit mass as well as the percentage budbreak caused a decrease in orchard efficiency. No differences between 1.5- and 3.0-m in-row spacings were found; spacings wider than 3.0 m reduced crop efficiency principally by decreasing fruit mass.