Computer simulation of cassava growth: a tool for realizing the potential yield

In this article, a process model (SIMCAS) for simulating the growth of cassava is proposed. Crop phenology was simulated as a function of growing degree days (GDD). New algorithms are used in this model to simulate different components of crop phenology. Branching is simulated as a function of the number of leaves and total dry matter produced. Standard methods were followed to compute solar radiation and photosynthesis. Sensitivity analysis confirmed the importance of canopy size on tuber yield. Algorithms for estimating stress due to a shortage of water, nitrogen and potassium are also included in this model. An attempt was made to predict the final yield under field conditions by multiplying stress values by potential yield. The model was tested under different environments. The tuber yield predicted by this model is in good agreement with the corresponding observed values in most of the cases. Estimation of stress due to a shortage of nitrogen, potassium and water is the key aspect of this model. This information can be used to manage stress and thereby achieve the potential yield. By improving the stress algorithm, this model will serve as a useful tool for achieving maximum cassava yield at optimum input level.