Induction of fruit calcium assimilation and its influence on the quality of table grapes

Sprays containing soluble Ca, polypeptidic N and Ti ascorbate in several combinations were applied to cv. Crimson table grape vines (Vitis vinifera L.). Foliar spraying resulted in the accumulation of N, P, K, Ca, Mg, Fe, Zn, Cu and Ti in the leaves, but not of Na, Cl or Mn. In the berries, Ca, Fe, Zn and Cu concentrations increased in the skin and flesh. These berries were also larger than controls, firmer, had a deeper external red colour, and their weight loss during postharvest storage was reduced. The increase in the Ca and micronutrient content of the fruit is explained as a consequence of the beneficial effect of Ti on absorption, translocation and assimilation processes. In turn, improved Ca assimilation by the fruit was responsible for the beneficial effects seen on firmness and storage life.