Simulation of growth and productivity of rice (Oryza sativa) under tropical monsoon climate

Simulation models in the field of agriculture are mathematical equations that represent the reactions occurring within the plant and the interactions between the plant and its environment to assess growth and productivity. In this study two simulation models, viz. CERES-Rice and ORYZA1, were validated to predict growth and productivity of 5 rice varieties (‘Lalat’, ‘Ranjit’, ‘Gayatri’, ‘Savitri’ and ‘Swarana’) under tropical monsoon climate of eastern India (Jatni, Khurda in Orissa) during rainy (kharif) season of 2003–2005. On validation it was observed that the simulated values of dry weight of leaves, weight of stems, weight of panicles, above - ground biomass, grain yield and leaf-area index (LAI) were not significantly different from the observed values for both CERES-Rice and ORYZA1. Only simulated specific leaf weight (mg/dm²) was found significantly different from the observed values. Based on the correlation between above-ground dry biomass at flowering stage and yield, grain yield of the rice can be predicted in advance, i.e. at least 30 days before harvesting the crop.