this wide variation being largely explained by sudden and catastrophic infestation by month stem borers, cicadas, white grub and Ramu stunt virus. To a lesser extent under continuous cultivation included decreases in pH, available phosphorus and exchangeable potassium, and some preliminary data suggest soil compaction. Leaf nutrient concentrations of nitrogen, phosphorus and potassium also declined slightly. It is concluded that yields were largely influenced by insect pests and diseases, but that the management of soil fertility is likely to become increasingly important once those problems have been solved.