Effect of different sources of nitrogen on the vegetative growth of andean blueberry (Vaccinium meridionale swartz)

Abstract

The Andean blueberry (Vaccinium meridionale Swartz) is a small wild shrub that grows in Colombia in sub-paramo areas. The berry has a high export potential due to the high content of antioxidants in the fruits. The objective of the present research was to evaluate the effect of fertilization with different nitrogen sources on the vegetative growth of plants with four treatments: a control of 0% N, 50%NH4+-50%NO3-, 100% NO3-, and 100% NH4+. The dose of 70 mg L-1 N was used in the treatments with application of N. The plants with best growth were those fertilized with ammonia sources. The treatment with 100% NH4+ obtained the highest average number of shoots (22) and leaves (254) per plant, and the highest dry weight of plant organs at 148 d after planting of rooted cuttings followed by treatment with 50%NH4+-50%NO3-. Applications of 0% N and 100% NO3- resulted in higher rates of anthocyanin synthesis and lower contents of chlorophyll in leaves regarding to the N sources containing NH4+. The plants fertilized with 0% N and 100% NO3- presented lesser growth than those fertilized with 50%NH4+-50%NO3-and 100% NH4+. This study allows to conclude that the Andean blueberry requires a fertilization plan with ammonia sources.