ISHS Acta Horticulturae 379: International Symposium on Quality of Fruit and Vegetables: Influence of Pre- and Post- Harvest Factors and Technology
LIGHT INFLUENCE ON KIWIFRUIT (ACTINIDIA DELICIOSA) QUALITY |
| Authors: | R. Biasi, G. Costa, P.J. Manson |
| Keywords: | fruit growth, shading, fruit colour |
| Abstract:
Light availability and distribution within the canopy strongly affect tree physiology and consequently vine productivity. In order to evaluate the effects of light on fruit quality in kiwifruit vines (Actinidia deliciosa), shading experiments were carried out on whole vines and individual fruits. Two shading levels (45% and 90%) were realized in a mature orchard by placing shade nets over trees. The highest shading intensity was applied at two different stages, i.e. before blooming and after fruit set. Single fruits on well-exposed vines were enclosed in paper bags (90% shading) for varying spans of time during fruit development. As well as vine productivity and fruit growth, fruit quality parameters were evaluated, i.e. fruit size and shape, flesh firmness, soluble solids concentration and fruit colour. All shaded vines showed higher fruit drop in comparison to unshaded ones, even at only 45% shade and with both early and late treatments, leading to reduced productivity. Light was essential for regular fruit development. Fruits on shaded vines showed reduced growth, but totally shaded fruits on light-exposed vines presented good size and shape. Lack of light negatively affected flesh firmness and soluble solids concentration. Fruit colour was only slightly affected by shading. Even 90% shade allowed fruits to develop their colour, with only a slight increase of peel paleness and a decrease of flesh colour. Flesh greenness was strongly inhibited only by total fruit shading. Good exposure of leaves rather than fruit is essential for regular kiwifruit development, but both conditions should be met for high fruit quality. The choice of proper planting systems as well as pruning intensity, therefore, need to be evaluated carefully in order to obtain a high quality product. | |
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