Relationship between Leaf Area Index and fruit size in kiwifruit

The relationship between Leaf Area Index (LAI) and fruit size was studied on two commercial orchards in Te Puke, New Zealand, during two seasons. On each orchard, pruning regimes were adjusted to produce either dense, or light canopies. The LAI of individual vines was estimated from the amount of light transmitted through the canopy and values ranged from 2.5 to 6.0. In the first season, crop loads ranged from 13 to 48 fruit per m(2) of canopy and fruit size was not closely correlated with either crop load or LAI. In the second season, crop loads were higher (21 to 70 fruit/m(2)). In each orchard, fruit size decreased as the crop load increased at a rate of 0.2 g/fruit/m(2) High values of LAI decreased mean fruit size at a rate of 5.8 g per unit LAI. These findings suggest that LAI can be as important as crop load in determining fruit size.