Abstract

Canopy development and production efficiency variations were evaluated in four sweet cherry (Prunus avium L.) cultivars: 'Bing', 'Lapins', 'Sweetheart' and 'Regina', grafted on different vigor rootstocks: 'Colt', 'Cab-6P, 'Maxma-14' and 'Gisela-12', and conducted in two training systems: Central Leader (CL) and Kym Green Bush (KGB), growing in Chile. Leaf indicators were calculated after tree defoliation. A principal components analysis (PCA) was conducted to select indicators that explain the variation among the combinations. Results showed that leaf size and number varied between different cultivar/rootstock combinations and training systems. By means of two principal components, the model employed could explain 72% of the data variability. The most relevant indicators for the PC1 were: leaf weight per hectare (0.98) and leaf area index (0.97), with a significant training system effect, whereas for the PC2 they were: leaf weight per leaf area (0.85) and production per leaf area (0.72), mainly for productive efficiency. In 'Lapins'/'Colt', the KGB system presented a higher weight and leaf area than CL, with almost double the leaf weight per hectare and leaf area index, due mainly to a 37% leaf area per tree and 20% higher tree number/ha in KGB. However, average production per leaf area reached 0.49 kg m(-2), without distinction between training systems.