Crop coefficient of cut gerbera with water supplementation in a protected environment

Abstract

The determination of the crop coefficient (Kc) is vital since, although gerbera cultivation is constantly expanding, there is little research on the evapotranspiration of the crop cultivated under a protected environment to obtain the correct irrigation management. The objective of this work was to evaluate the evapotranspiration and crop coefficients of cut gerbera, cultivated in protected environment. The reference evapotranspiration (ETo) and crop evapotranspiration (ETc) were obtained through the Penman and weighing lysimetry methods, respectively. The experimental design used was completely randomized, consisting of five irrigation treatments (120, 100, 80, 60, and 40% of the water retention capacity), with ten replicates each, totalizing 50 experimental units. The Kc was evaluated using the irrigation lamina that presented the highest production of floral stems among the tested treatments, obtained through the relation between ETc and ETo. The mean of the crop coefficient ranged from 0.72 in vegetative period I, 0.81 in vegetative period II, 0.85 in flowering I, 0.89 in full flowering II, 1.33 in full flowering III, and 1.06 in end of the flowering I. The water consumption for the cut gerbera crop in the treatments with water availability ranged from 225.87 to 523.58 mm. Therefore, the crop coefficients proposed for the different phenological stages of the gerbera were efficient for irrigation management.