MODEL OF THE DEVELOPMENT AND BULKING OF POTATOES (SOLANUM-TUBEROSUM-L) .1. DERIVATION FROM WELL-MANAGED FIELD CROPS

A simple empirical model is presented which describes the development over time of a potato crop and the pattern of tuber bulking. It was derived from analyses of time-series of yields obtained from experimental plots and carefully managed commercial crops grown in contrasting climatic regimes. It is consistent with experimentally derived knowledge of potato physiology. The inputs for the model are weekly means of the maximum and minimum temperatures from emergence to cessation of bulking, and of insolation and daylength for 3 weeks following emergence, together with an estimate of the maximum soil-water deficit experienced during bulking. Operation of the model is so easy that it can be employed routinely by farmers and extension officers using only a pocket calculator. The model provides a new tool for the analysis of experiments with potatoes in which yield is measured throughout the bulking period. It has also been modified to provide a version directly applicable to populations of commercial crops grown in a district. © 1979.