Resumo

RISCO ARIAS, David; GUTIERREZ ALBAN, Alberto Cristóbal  e  BUENANO SANCHEZ, Marcia Eduvijes. Growth, yield and quality in broccoli grown under different nitrogen fertilizer rates. Investig. Agrar. [online]. 2016, vol.18, n.1, pp.44-49. ISSN 2305-0683.  https://doi.org/10.18004/investig.agrar.2016.junio.44-48.

Broccoli is one of the most economically important crops in the Ecuadorian Andes. Nitrogen fertilization directly affects its production because it is one of the most important nutrient for plants. In order to evaluate broccoli crop response to nitrogen fertilizer, a study was carried out   during 2014 in a randomized block design with five treatments and three replicates. The treatments were 200 kg ha^-1(N₂₀₀), 250 kg ha^-1 (N₂₅₀), 300 kg ha^-1 (N₃₅₀), 350 kg ha^-1 (N₃₅₀) and 400 kg ha^-1 (N₄₀₀) of nitrogen fertilizer in the form of ammonium nitrate (33%). The following variables were evaluated: stem length and diameter, number of leaves, head weight and diameter at harvesting, total hectare yield, nitrogen use efficiency and nutrients concentration. Stem length was the highest in N400 treatment at 50 days after sowing, but vegetative growth was not affected by treatments at 70 days after sowing. Conversely, in the harvesting parameters, N₃₅₀ treatment yielded the highest crop production (17,81 t ha^-1), higher than that of  the N₄₀₀ treatment (14,02 t ha^-1). However, treatment N₃₅₀ scored lower concentrations of nutrients such as potassium. The N₂₀₀ treatment yielded the lowest production but made a more efficient use of nitrogen. This experiment showed the adverse effects of an excess of nitrogen fertilization on broccoli production and the importance of carrying out assays for different climatic and soil conditions.

Palavras-chave : Brassica oleracea var. italica (L.); quality; nitrogen; potassium; production.

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