Published online by Cambridge University Press: 03 October 2008
In spite of large year-to-year variations in clove yields, production in the islands of Zanzibar and Pemba is often in synchrony and the annual harvests of the two islands are correlated with similar variables. Clove harvests are positively correlated with rainfall in October to February two years before the harvest and negatively correlated with the harvest in the previous year and rainfall around July, and October to December of the year before the harvest. It is likely that rainfall in these periods affects vegetative growth of the clove tree and clove bud differentiation.