YIELD FORECASTING

While crop yield forecasting is important for national food security, including early determination of the import/export plan and price, it is also important in providing timely information for optimum management of growing crops. Following a brief review of the current status of the existing three methods of yield forecasting (field measurements of standing crops, remote-sensing and crop environment models), this paper focuses on rice yield forecasting by Simulation Model for Rice- Weather Relationships (SIMRIW) (Horie, 1987). SIMRIW is a simplified process model for predicting crop growth and yield from daily weather. This model integrates the processes of ontogenetic development, biomass accumulation and yield formation through their rational simplifications. The model explained the locational and yearly variations of rice yield due to climate and weather in Japan and the USA. A system for real-time monitoring and forecasting of regional rice growth and yield has been developed by combining this model with mesh-weather information systems. Usefulness of this system in regional yield forecasting and crop management is demonstrated and discussed.