Water management and crop coefficients for pot chrysanthemum

Chrysanthemum is one of the most commercialized flower species in Brazil, however, there is little information related to the correct water management of the crop. Thus, the work seeks to determine the crop evapotranspiration (ETc) and obtain the cultural coefficients (Kc) of the pot chrysanthemum, in addition to assessing the water use efficiency (EUA) of the crop under different irrigation managements. The experiment was conducted in a protected environment in Santa MariaRS, which a completely randomized design (DIC) was used, with five treatments based on the capacity of water retention in the vessel (CRV) (40, 60, 80, 100 and 120% CRV), with 16 repetitions, each pot was considered one repetition. ETc was determined by weighing Lysymetry, ETo was calculated by six different equations: Benevides-Lopez, Camargo, Linacre, Jensen-Haise, Hargreaves and Ivanov. Kc was obtained by the relationship between ETc and ETo. The evapotranspiration of the culture ranged between 153 and 264 mm. There was no significant difference in the EUA between the treatments studied. The average Kc was 0.98 for the vegetative phase, 1.29 from the beginning of the reproductive phase to the point of commercialization and 0.85 until the end of the reproductive phase.