evaluation of cropsyst-wheat for simulating of development, growth and yield in response to planting date

the crop simulation models are heuristic tools in order to determine optimal of management strategies and analyzing yield stability in agroecosystems. the objective of this study was to evaluate cropsyst model ability for simulating of development, growth and yield of wheat cultivars from golestan province in response to planting date. the results of model evaluation were acceptable so that, the trend of observed and simulated days to anthesis and maturity values in response to planting date, were similar. on the other hand, the differences between observed and simulated day to phenologic different stages in whole planting dates were statistically not significant. as the experimental data showed, by delay in planting, the yield was declined. the same response is showed for simulated yield. root mean square error (rmse) of yield in whole planting dates and for kohdasht, tajan and zagros cultivars were 295, 345 and 274 kg.ha-1 that were 8.7, 10.6 and 8.9 percentage of mean respectively. as a result, despite of absolute differences between observed and simulated values, cropsyst-wheat model can partly acceptable simulate the response of development, growth and yield of wheat cultivars from province to planting date.