Effects of Fruiting, Defoliation and Ring-Barking on the Accumulation and Distribution of Dry Matter in Branches of Coffea Arabica L. in Kenya

Abstract

SUMMARYWhole branches were removed from trees in the field, at regular intervals, to follow the increase in dry weight of fruits and new vegetative growth. Information on the partition of carbohydrates was gained by comparing the growth of untreated, defoliated, de-blossomed and ring-barked branches. Untreated branches increased in weight rapidly when their fruits began to expand, probably because they imported carbohydrates, and their net photosynthetic capacity increased. More young fruits were shed from defoliated than from untreated branches, thus partially compensating for loss of leaf. Non-fruiting, and sometimes fruiting, branches exported a considerable amount of assimilate during the dry seasons, when the trunk-root system was a relatively important dry matter sink. When there were many fruitless branches on fruiting trees, the fruiting branches imported carbohydrates from them during the whole period of fruit growth, whereas fruitless branches imported carbohydrates only when there was a ‘flush’ of shoot growth.