Management of boron fertilization in eucalyptus cultivated in the low altitude Cerrado region in Entisol

This study aimed to compare the residual effect from boron (B) sources in the planting furrow as well as foliar applications of B, and the top dressing reapplication of micronutrient in boron nutrition, wood productivity and the tree fork of the eucalyptus cultivated in an Entisol. The experiment was assembled in a subdivided plots scheme, arranged in a factorial scheme of 3 x 2 x 2, with the first factor being: 0 kg ha(-1) of B, 1 kg ha(-1) of B using borogran fertilizer or 1 kg ha(-1) of B using boric acid fertilizer in the furrow; with or without B application via leaves (boric acid); and the last factor 2, it refers to the subplots that received or not the top dressing application of B in the soil at 34 months after the planting at the 1 kg ha(-1) dose of B (boric acid). Boron sources, at a 1 kg ha(-1) dose, as well as the foliar nutrient applications, at 4 and 10 months after planting, reduced the tree fork percentage of eucalyptus trees. The 1 kg ha(-1) application of B in the eucalyptus plantation (I144 clone) was not enough in a soil with average B content, being necessary the top dressing reapplication of this nutrient, with positive reflexes in the B content in the soil, and consequently, in the B foliar concentration and wood productivity.