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

The effect on Coffea arabica cv. Ruiru 11 of training the trees on a single or two stem system at planting densities of between 1600 and 4800 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 up with the production levels of the single stem system faster in the wetter than in the drier zone. Yields of clean coffee increased with tree density up to 4000 trees ha-1 at all sites, irrespective of tree training method, but increased more slowly at populations of more than 4000 trees ha-1, especially in the drier zone. The proportion of large, grade A, coffee beans was not significantly influenced by the treatments studied.