Abstract
In an irrigated NPK fertilizer trial on young Upper Amazon cacao grown under light shade on rich alluvial fans, there was no significant response to the main effects of N, P and K in terms of weight of wet beans or number of pods per hectare, although N significantly increased the weight of wet beans per pod. N applied in the absence of other nutrients significantly decreased the weight of wet beans and number of pods per hectare. N and K interacted to increase significantly the weight of wet beans per hectare above that obtained when these nutrients were applied separately. Significant increases in the weight of wet beans per hectare were obtained from P in the absence of K and from K in the absence of P.
