Influenza dei fattori ambientali sul trasporto e accumulo di elementi minerali in foglie e frutti di piante di actinidia.

In this study, the effect of light availability on actinidia leaf and fruit N, P, K, Ca and Mg accumulation is reported. At fruit-set, exposed and shaded treatments were imposed. Fruit and leaf transpiration was measured using a portable gas exchanges analyser (ADC-LCA4). Sap flow was monitored on whole canes using the Dynagage Sap-Flow (heat balance method). Transpiration of exposed leaves was on average 66% higher than the one of shaded leaves. Sap flow of exposed canes was on average 53 g mE-2 per day; the shadow treatment determined a 60% decrease of sap flow. These differences affected the accumulation of those minerals, notably calcium, which are transported mainly via xylem. Fruit calcium content reached approximately 40 mg fruitE-1 in exposed fruits, while in the shaded ones it was 23 mg fruitE-1. Our results suggest that a greater light availability can promote calcium accumulation. Therefore, the accurate training system management, favouring light interception by canopy and fruits, could be a tool for fruit quality improvement.