AquaCrop evaluation to simulate wheat production and planting date in Fars province

Wheat canopy cover, biomass, grain yield and planting date under deficit irrigation were simulated by AquaCrop in Darab and Zarghan of Fars province. The 2015-2016 growing season and 2016-2017 and 2017-2018 growing seasons were used for model calibration and validation, respectively. Water content, canopy cover, biomass and grain yield were used to determine the calibration parameters in the first year. The calibrated model showed high accuracy in simulating canopy cover, biomass and grain yield. CRM, NRMSE, d and R2 in Darab were 0.03, 0.22, 96 percent and 92 percent for canopy cover, -0.10, 0.24, 92 prcent and 92 percent for biomass, and - 0.03, 0.06, 80 percent and 82 percent for grain yield, respectively. In Zarghan, these values were 0.06, 0.25, 91 percent and 89 percent for canopy cover, -0.08, 0.24, 91 percent and 87 percent for biomass and -0.02, 0.11, 71 persent and 86 percent for grain yield, respectively. Model application in different scenarios showed that the maximum delay in planting date is 5th November in Zarghan and 5th December in Darab. Grain yield was reduced to 3, 17 and 28 percent in 25 percent irrigation reduction and 15, 27 and 45 in 50 percent irrigation reduction in wet, normal and dry years, respectively.