EFFECT OF NITROGEN FERTILIZATION ON FRUITING AND VEGETATIVE PERFORMANCE, FRUIT QUALITY AND POST-HARVEST LIFE OF KIWIFRUIT CV HAYWARD

The influence of nitrogen at four different fertilizer levels (0, 150, 300 and 450 kg N ha^-1) was evaluated for three consecutive years in a ‘Hayward’ kiwifruit orchard located in north-east Italy on a coarse textured soil.

In terms of vegetative growth, nitrogen applications increased shoot length, the number of leaves/shoot, leaf area and consequently leaf area index (LAI). values.
Leaf efficiency was evaluated by measuring assimilation rates at increasing light intensities: the greater the nitrogen supplied, the higher the assimilation rate.

In terms of fruit production and quality, nitrogen applications tended to increase yields/vine and average fruit weight.
Fruit growth (diameter, length, volume, fresh and dry weight) was also increased by nitrogen: the highest values were measured for fruit from vines receiving nitrogen and the lowest in control vines receiving no nitrogen.
Fruit quality was not substantially affected by the nitrogen application, although the percentage of marketable fruits was slightly enhanced by 150 kg N ha^-1 nitrogen and reduced by the higher concentrations.
The percentage of "fan and fasciated" fruits varied from year to year but was always higher in vines receiving nitrogen.
Soluble solids content as well as flesh firmness, both at harvest and after storage, were not affected by increasing nitrogen applications.

III International Symposium on Kiwifruit

G. Costa, O. Lain, G. Vizzotto, S. Johnson

Actinidia deliciosa, photosynthesis, leaf nitrogen concentration, fruit nitrogen concentration

https://doi.org/10.17660/ActaHortic.1997.444.43