SEASONAL CHANGES OF GLUCOSE, POTASSIUM AND RUBIDIUM IN ‘GORDAL SEVILLANA’ OLIVE IN RELATION TO FRUITFULNESS

Fruitfulness influences the partitioning of assimilates in olive during the reproductive phase. Seasonal changes of the concentration of glucose, potassium and rubidium in different organs indicated that the current-year growth was the main sink in the de-fruited bearing shoot while the fruit was in the fruiting shoot. Normal fruit of ‘Gordal Sevillana’, a cultivar with normal and parthenocarpic fruits, showed higher rate of growth and content of assimilates and mineral nutrients than parthenocarpic fruit from 15 days after full bloom (FB+15) to harvest. Consequently normal fruit was the strongest sink in this period. Those data suggest that the sink strength and therefore the assimilates partitioning is a major factor in regulating fruit set in olive.