Rendimento do cebola no solo com esterco bovino e nitrogênio

Abstract

The onion is the third herb in economic importance for Brazil, being surpassed only by the potatoes and tomatoes. This study aimed to with this work to evaluate the effect of different levels of cattle manure and nitrogen on growth and yield of onion. The work was conducted in field conditions, In the Federal University Paraíba, Areia-PB, between June and November of 2015. The experimental design was completely randomized blocks, in factorial scheme 6 x 2 corresponding to six doses of cattle manure (0; 10; 20; 30; 40 e 50 t ha-1 ), and presence and absence of nitrogen, in four repetitions. Were evaluated: height of plants-1, dry and green in the aerial part, average mass of bulbs, total and commercial yield of bulbs, classification of bulbs and leaf N content. The height of plants of onion reached the maximum at 40 DAT, 52.0 and 44.2 cm in the doses of 32.8 and 31.6 t ha-1 of cattle manure, respectively, in the presence and absence of N. Independent of the treatments the accumulation of green mass in onion increased with time. The average mass of onion bulbs calculated by derived reached maximum values, 143 and 116 g in the doses of 30.5 and 35.1t ha-1 of cattle manure, respectively, with and without nitrogen. The total yield of bulbs has reached the maximum of 63.5 t ha -1 at the dose of 28.8 t ha-1 of cattle manure in the presence of nitrogen. The dose of 27 t ha-1 of cattle manure in the presence of nitrogen, was responsible for the maximum commercial yield of bulbs of 50 t ha-1 , without nitrogen was obtained productivity of 36 t ha-1 of commercial bulbs, according to the dose of 28.2 t ha-1 of cattle manure. In the classification of onion was not checked bulbs considered tailings. The bovine manure and nitrogen reduced the production of bulbs with diameters smaller (classes 1 and 2), and increased production of bulbs with diameters larger (class 4). The leaf N content was 24.6 g kg-1 obtained at the dose of 27.2 t ha-1 of cattle manure with nitrogen, and 21.8g kg-1of N in the dose of 31.2 t ha-1 of cattle manure.