Growth and physiological parameters in conilon coffee seedlings fertilized through foliar application of tannery sludge

Currently, industries are increasingly concerned about the destination of their waste, and one of the solutions found may be the reuse of certain waste in the form of organic fertilizers. Thus, the aim of this work was to evaluate the growth and physiology of conilon coffee seedlings under foliar application of liquid tannery sludge as an alternative to fertilization. The experiment was conduced in a greenhouse. The experimental design was in randomized blocks, with eight replications and seven treatments, which consisted of different concentrations of tannery sludge (6.20, 8.80, 11.47, 14.10 and 17.60 mL of sludge tannery diluted in 1 L of water), a conventional treatment with urea and a control treatment using only water. Growth and physiological characteristics were evaluated through gas exchange, fluorometric analysis and color analysis using the Colorimeter. The conilon coffee seedlings fertilized with 14.10 and 17.60 mL L −1 showed a satisfactory growth pattern. The doses of tannery sludge used in this study did not promote changes in color analysis and indices obtained by fluorimetry, except for flavonoids, in which the highest dose promoted greater synthesis of this secondary metabolite. Doses below 14.10 mL L −1 promoted changes in gas exchange, however, leaf photosynthesis was only compromised with doses equal to or less than 8.80 mL L −1 .