Generalization of irrigation scheduling parameters using the growing degree days concept: application to a potato crop

An accurate irrigation scheduling methodology is necessary in crops with high water stress sensitivity and production cost. This involves the estimation of the scheduling parameters related with crop water requirements during phenological stages under different irrigation application systems. This paper presents several models to represent the parameters of irrigation scheduling based on growing degree days (GDD) such as: management allowed soil water depletion (MAD), rooting depth (Rd) and crop coefficient (Kc). The proposed models were applied accurately to schedule irrigation in two commercial fields of potato under two irrigation methods: surface and sprinkler irrigation. Results show that the model predicted irrigations in a consistent and logical manner. The proposed models are versatile, feasible and easily implemented in irrigation scheduling computer programs.