Nutritional status of southern highbush blueberry cultivars under tropical climate conditions of Central Brazil

Resumo

Global blueberry production has been increasing annually. The cultivation area in Brazil has expanded with the introduction of new low-chill cultivars, particularly those from the Southern Highbush group. Assessing the nutritional status of plants from different cultivars is essential for successful cultivation. In this context, the objective of this study was to evaluate the nutritional status of Southern Highbush blueberry cultivars (Biloxi and Emerald) under tropical climate conditions of Brasília, Distrito Federal, Brazil. The experiment was conducted in 2023 and 2024 at the Fruit Production Sector of the Biology Experimental Station (EEB) of the University of Brasília (UnB). The region's climate is classified as Aw, tropical savanna, with dry winters and rainy summers, according to the Koppen-Geiger classification. The experiment was conducted in a randomized block design, with 10 replications and 10 plants per experimental unit, totaling 200 plants. The treatments evaluated consisted of two cultivars: Emerald and Biloxi. Leaves were analyzed for nutrient contents: macronutrients included nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), expressed in grams per kilogram (g kg^-1); and micronutrient contents included boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), expressed in milligrams per kilogram (mg kg^-1). The cultivars had a significant (p < 0.01) effect on leaf macronutrient (N, P, K, Ca, Mg, and S) and micronutrient (Fe, Mn, Cu, Zn, and B) contents in both years evaluated. The cultivar Emerald exhibited higher accumulation of N, P, Zn, and Cu, whereas the cultivar Biloxi showed greater accumulation of K, Ca, Mg, S, Fe, Mn, and B in leaf tissues.