Abstract:
The objective of this study was to calibrate and test Aqua Crop for tomato (Lycopersicon esculentum) grown under
deficit and full irrigation. Two field experiments were carried out in the tropical humid coastal savanna zone in Mfantseman
district of the Central Region of Ghana. Data from the first experiment were used to calibrate the model while data obtained
from the second experiment were used to validate the model. The calibrated Aqua Crop model concentrated on its
performance to predict crop yield and seasonal crop water requirement (ETc). Four treatments were investigated: T1 (no
irrigation after plant establishment), T2 (50% ETc restoration), T3 (100% ETc restoration up to beginning of flowering, then
50% ET
c restoration) and T4 (100% ETc restoration). The results revealed that Aqua Crop was able to simulate the yield of
tomato for T2-T4 with the exception of Treatment T1 which was simulated with the highest deviation of 45.1%. On the other
hand, the model was able to simulate the seasonal water requirements to an appreciable degree in both experiments. It must be
pointed out that the calibration of Aqua Crop suffered from a lack of data on the progress of crop canopy cover which is a very
important parameter used in developing the model