Leaf Carbohydrates and Flower Formation in Citrus

The carbohydrate contents of the leaves of satsuma mandarin (Citrus unshiu Marc.) trees were altered before or during the low temperature flower induction period to determine the relationship between gross levels of carbohydrates and flower formation. Early removal of the fruit and girdling of the branches on either fruiting or defruited trees caused an accumulation of carbohydrates in the leaves and increased flower formation. Shading the trees resulted in a transient reduction in leaf carbohydrate levels and in a decrease in flower formation. Although a relationship between carbohydrate levels and flowering was consistently found, our results show that the gross levels of carbohydrates do not appear to limit flower formation in citrus.