Effects of micronutrient mixture foliar spraying on sunflower yield under water deficit and its evaluation by AquaCrop model

Abstract

AquaCrop is a very famous model in the world for evaluating the crop water productivity. FAO has developed the AquaCrop model as a leading and powerful scientific tool for simulating the response of different field crops to managing quantitative and qualitative irrigation. The experiment was cultivated on the farm of National Research Centre of Research and Production at El-Nubaria district, El-Buhaira Governorate on summer season of  the year 2018 and 2019, treatments were 80, 60 and 40 % of water holding capacity (WHC), and Micronutrient  mixture 4 levels 0, 1, 2 and 3%. Results found that the simulated and observed values of seed yield were rather well in agreement for the water stress treatments. This means that differences in vegetative growth, yield and water productivity of sunflower crop had no significant effect on the calibration results. There is an inverse relationship between the water productivity and water treatments, while a direct correlation was found between water productivity and Micronutrient  mixture coefficients. NPK content, and the protein ratio in sunflower leaves was generally increased by increasing the mixture of Micronutrients. It could be concluded that using maximum of water treatment, 80% WHC and the mixture of Micronutrients, this due to that there is a direct relationship between the study factors, the characteristics of the vegetative growth and yield of the sunflower plants, that is, the more water is added, the more measured values will be simulated by the Aquacrop model.