Reproductive patterns of 1-year-old mixed shoots in different olive cultivars in Central Italy

Abstract

The increase of plant density in new olive orchard systems requires a deeper investigation about plant architecture to understand growth, branching pattern and yield and to select most suitable cultivars. The spatial arrangement of vegetative and reproductive structures helps to explain the fruiting attitude of the plant at different levels: the whole tree, the productive branch and the fruiting shoot. The objective of the present study was to investigate the reproductive attitude of 1-year-old mixed shoots in six olive cultivars grown in central Italy in order to determine inflorescence and fruit distribution and identify correlations between vegetative-reproductive variables. Results showed a differing inflorescence and fruit distribution along the shoot axis: a higher number in the median-distal portion for the cultivars 'Arbequina', 'Don Carlo' and 'Giulia', in the median-basal portion for 'FS17' and more homogeneous for 'Arbosana' and 'Koroneiki'. A higher fruit number with increasing length of 1-year-old mixed shoot was registered, but with a shallow slope relationship compared to the number of flowers per shoot. After fruit set, the crop load remained constant until harvest. Cultivars showed a different vegetative-reproductive pattern in the climatic conditions of central Italy with differences between all cultivars. This study contributes to understand the reproductive pattern of 1-year-old mixed shoot in olive, suggesting a different suitability of the cultivars to different planting density systems.