Evaluation of the FAO Aquacrop Model for Bell Pepper (Capsicum annuum L.) Crop Water Productivity under Deficit Irrigation

Abstract

With the drive to determine solutions for water scarcity during crop production, crop
production models, such as AquaCrop, were used to model the crop water productivity
of bell pepper. This study was conducted in La Paz, Zamboanga City, Philippines, to
simulate and validate the crop water productivity of the Emperor F1 variety of bell
pepper cultivated under deficit irrigation. Bell peppers were produced until the onset
of flowering, randomly arranged according to three levels of irrigation applied, which
are 80%, 70%, and 60% of the full irrigation treatment. Calibration of AquaCrop was
conducted following a full irrigation treatment. The model was validated following the
variation in the amount of irrigation applied. Plant height, leaf length, fresh and dry
above-ground biomass, and crop water productivity were determined and statistically
analyzed. Modeling resulted in excellent goodness of fit for the RMSE test and
moderate agreement for the index of agreement. This study showed that deficit
irrigation is a viable method in water management for bell pepper production,
especially in farm areas where water rationing is limited. Using AquaCrop to simulate
crop water productivity is a feasible solution to help farmers determine whether the
intended irrigation strategy will best fit bell pepper production.