The objective of this work was to study the effect of nitrogen fertilization at establishment and development of star fruit (Averrhoa carambola L.), cv. B-10, orchads and the acidification of Eutrustox soil. The experiment design was in randomized blocks, comprising five treatments corresponding to different nitrogen (urea) rates, with four replications. At the plant establishment, N rates were zero, 30, 60, 90 and 120 g plant-1 of N and, at the 1st, 2nd and 3rd years of experimentation, two fold, three fold and four fold of initial rate. Nitrogen fertilizer on star fruit at establishment, after the second year of experiment, result in significant pH reduction which increase potential acidity and decrease potassium, calcium and magnesium concentrations, as well as the sum of bases and base saturation of soil. Star fruit without nitrogen fertilization show lower foliar N concentration, in relation to those which received fertilizer, and until the third year of experimentation did not flower. In the third year of experimentation, rates between 110 and 180 g plant-1 of N promote the best development to star fruit at orchard establishment, foliar N concentration, index SPAD as well as the best fruit production.
Averrhoa carambola; nitrogen fertilizers; nutritional state; fruit production
