ALCEPAS,an onion growth model based on SUCROS87. II. Validation of the model

Summary

A dynamic simulation model for onion growth at potential production level (ALCEPAS), presented in a previous paper, was validated using data on leaf area index, bulb and green leaf dry-matter production, bulb formation and day of fall-over from independent trials at four locations. The model performance in terms of bulb dry-matter production was good under environmental conditions close to the optimum, but insufficient under stress situations. The model overestimated leaf area index and green leaf dry matter. Bulb formation was simulated satisfactorily, while the time of 50% fall-over was simulated too early at low plant densities.