Evaluation of Aquacrop model for decreasing water stress effects due to different wheat planting date

Planting date is one of the effective factors for crop yield production that appropriate chooses; it can increase plant yield production. One of the advanced and practical models in the water, soil and plant is Aquacrop that has high ability and performance in different crop simulation and environmental conditions. In this regard using of long term meteorological data of 14 years (2000-2014), the effect of general different planting dates of wheat (within 7 days) in the Hamidiyeh region using Aquacrop model was investigated. In order to validate and comparing the results of Aquacrop model simulation with measured data, two pilots were considered. The results of yield measured data in two pilots in 2014-2015 indicated that if wheat is cultivated in the range of the second decade of November, the wheat yield production can increase from 2 to 2.6 ton/ha. The results of the model simulation and measured data showed that the Aquacrop model has high performance and ability for wheat yield simulation based on wheat planting date and can be used in the similar conditions with reasonable accuracy(root mean square error and absolute error are 0.26 and 11% respectively) in different planting dates for wheat yield simulation. Regarding to probability of rainfall occurrence in second decade of November (about 37 %), selecting planting date in that range accompanying with increasing soil surface moisture (about 80%), than planting date in first decade, can increase seed germination. In this condition water stress is less and more yields are predictable.