In 1968-9 and 1970-1 small-scale experiments were set up on over a hundred farms in Barbados, simple enough for farmers to carry out with a minimum of supervision. Results were obtained from more than 70 in each year. NK fertilizing gave no increase in yield in 1968-9, but a significant increase of 800 lb per acre in 1969-70. In each year NPK gave a highly significant increase of 1000 lb per acre. There was also a general increase in yield with increasing rainfall up to about 40 inches during the growing season and with closer than normal spacing especially under conditions of low rainfall. Planting later than usual led to marked decreases in yield.