A Model to Simulate Sweet Potato Growth

Abstract

Abstract: A new paper a process model (SPOTCOMS) for simulating growth of sweet potato is proposed by modifying the earlier model MADHURAM. Crop phenology was predicted as a function of growing degree days (GDD). Crop growth was divided into three phases i.e. first phase from planting to tuber initiation, middle phase from tuber initiation to the beginning of tuber bulking and the final phase from the beginning of tuber bulking to harvest. Vine growth rate and tuber growth rate in terms of GDD were worked out. Branching event also was predicted as a function of number of leaves. For computing solar radiation, photosynthesis and partitioning of dry matter, methods used in MADHURAM model was followed. Sensitivity analysis confirmed the importance of leaf area and the length of middle phase on the tuber yield. The model was tested under three different environments. The yields predicted in this model are in good agreement with the corresponding observed values in most of the cases. Prediction number of tubers was also reasonably accurate. However prediction of number of leaves and branching deviated considerably from the observed value. However, predictions made by this model are in better agreement with the observed values in the case of number of tubers and tuber yield than MADHURAM model