INFLUENCE OF TREE TRAINING AND PLANT-DENSITY ON YIELDS OF AN IMPROVEDCULTIVAR OF COFFEA-ARABICA

The effect on Coffea arabica cv. Ruiru 11 of training the trees on a s ingle or two stem system at planting densities of between 1600 and 480 0 trees ha-1 during the first production cycle after establishment was studied at three contrasting sites in Kenya. Training tree growth in the two stem system significantly depressed yields from the first two crops at all sites, irrespective of plant density, but yields caught u p with the production levels of the single stem system faster in the w etter than in the drier zone. Yields of clean coffee increased with tr ee density up to 4000 trees ha-1 at all sites, irrespective of tree tr aining method, but increased more slowly at populations of more than 4 000 trees ha-1, especially in the drier zone. The proportion of large, grade A, coffee beans was not significantly influenced by the treatme nts studied.