Growth of pineapple 'Vitoria' irrigated under different population densities, sources and doses of nitrogen/Crescimento do abacaxizeiro 'Vitoria' irrigado sob diferentes densidades populacionais, fontes e doses de nitrogenio

In order to evaluate the growth of the 'Vitoria' pineapple irrigated and submitted to increase population density and doses of nitrogen in the North of the state of Minas Gerais, the experiment was set in a factorial scheme 5 x 4 x 4, corresponding to five doses of N (0, 5, 10, 15 and 20 g plant-1), four plants populations (51,282; 76,923; 90,909 and 126,984 plants [ha.sup.-1]), and at four times of evaluation (270, 360, 450 e 540 days after planting--DAP), using urea or bovine manure as source of N. At 540 days after planting-DAP (time of flower induction), it was evaluated the effect of sources of N by means of factorial 2 x 5 x 4 that was composed of: two sources of N (urea and bovine manure), five doses of N and for plant populations as cited before. It was used a design in randomized blocks, with three replications, with Micropropagated plants of 'Vitoria' cultivar. It was evaluated growth characteristics of the plant (number of emitted leaves, length and weight of the "D" leaf and stem diameter) and fruit weight with or without crown. It was not observed interaction between planting density, doses of N and days after planting (DAP). The increase in planting density decreased the diameter of the stem of the pineapple, however, did not affect the fruit weight, indicating the possibility of higher plant population for productivity increasing. The use of urea as nitrogen source promoted greater growth and weight of pineapple fruits. The use of N as urea and manure increased growth of pineapple and linearly increased fruit weight, indicating the dose of 20 g plant-1 of N in the urea form as recommendation for growing pineapple 'Vitoria' irrigated. Index terms: Ananas comosus var. comosus, length and weight of the "D" leaf, fruit weight. Com o objetivo de avaliar o crescimento do abacaxizeiro 'Vitoria' irrigado, submetido ao aumento da densidade populacional, e doses de N na regiao norte de Minas Gerais, foi instalado um experimento em esquema fatorial 5 x 4 x 4, correspondendo a cinco doses de N (0; 5; 10; 15 e 20 g [planta.sup.-1]), quatro populacoes de plantas (51.282; 76.923; 90.909 e 126.984 plantas [ha.sup.-1]) e quatro epocas de avaliacao (270; 360; 450 e 540 dias apos o plantio--DAP), utilizando ureia ou esterco bovino como fonte de N. Aos 540 dias apos o plantio--DAP (epoca de inducao floral), foi avaliado o efeito das fontes de N por meio do fatorial 2 x 5 x 4, que consistiu em : duas fontes N (ureia e esterco bovino), cinco doses de N e quatro p