A PEANUT SIMULATION-MODEL .1. MODEL DEVELOPMENT AND TESTING

A biophysically robust crop simulation model can assist industry plann ing and farmer decision-making via simulation analyses to quantify pro duction potential and production risks. Accordingly, we developed a si mple, yet mechanistic peanut simulation model for use in assessing cli matic risks to production potential for both irrigated and dryland con ditions. The model simulates pod yield, biomass accumulation, crop lea f area, phenology, and soil water balance and is suitable for applicat ion over a diverse range of production environments. The model uses a daily time step, utilizes readily available weather and soil informati on, and assumes no nutrient limitations. The model nas tested on numer ous data from experiments spanning a broad range of environments in th e tropics and subtropics. The model performed satisfactorily accountin g for 89% of the variation in pod yield on data sets derived from inde pendent experiments, which included crops yielding from 1 to 7 t ha(-1 ). Limitations of the model and aspects requiring better understanding to improve quantification are discussed. Despite some limitations, th e model attains a useful degree of predictive skill for a broad range of situations and environments. This outcome is testimony to the utili ty of the simple, generic framework used as the basis for this model. The model is suitable for simulation studies aimed at assisting indust ry planning and farmer decision-making.