INFLUENCE OF NITROGEN-FERTILIZER AND PLANT-DENSITY ON GROWTH AND YIELD OF ARABICA COFFEE DURING THE 1ST PRODUCTION CYCLE IN KENYA

Field interactions between nitrogen rates of application from 0 to 400 kg N/ha/yr and three coffee tree densities, 1329, 2658 and 5320 trees /ha, were evaluated during the first production cycle after establishm ent in Kenya. Application of more than 50kg straight N/ha/yr at Ruiru (east of Rift Valley) and Koru (west of Rift Valley) did not give sign ificantly higher yields of clean coffee regardless of the tree density evaluated. The lowest tree density of 1329 trees/ha produced signific antly (p = 0.05) lower yields of clean coffee than the higher tree den sities of 2658 and 5320 trees/ha. Clean coffee yield production was no t significantly different among the higher tree densities of 2658 and 5320 trees/ha at Koru site. Proportions of the large grade ''A'' sized beans were significantly (p = 0.05) lower in high nitrogen rates of a pplication treatments. High density planted plots contained higher res idual soil moisture content with thinner but taller coffee tree stems. Productive wood was highest under the medium tree density of 2658 tre es/ha.