'Gigante' cactus pear cultivated at different population densities in a mechanizable arrangement/Palma forrageira 'Gigante' cultivada em diferentes densidades populacionais em arranjo mecanizavel

Cactus pear is a crop adapted to the climatic conditions of the Brazilian semiarid region, so it has contributed to the socioeconomic development of this region. The objective of this study was to evaluate the response of'Gigante' cactus pear cultivated at different population densities in a mechanizable arrangement. The experimental design was in randomized blocks, with six population densities: 22,857; 34,286; 51,428; 62,857; 80,000 and 95,000 plants [hg-1] and four repetitions. The following variables were evaluated: plant height, number of cladodes, cladode length, cladode width and cladode area index, green and dry matter yields, extraction/export of nutrients and soil chemical characteristics. Increase in population density in a mechanizable arrangement decreases the number of cladodes and increases the cladode area index. The maximum green and dry matter yield of cactus pear cultivated in arrangement that allows mechanization is expected with populations of 69,111.79 and 64,445.91 plants [hg-1],respectively. Maximum values of extraction/export of nutrients in cactus pear tissue are expected at intermediate population densities (62,721.52-74,741.93 plants [hg-1]). Soil potential acidity has maximum value with 64,525.51 plants [hg-1]. Key words: Opuntia ficus-indica, yield, management A palma forrageira e uma cultura adaptada as condicoes climaticas do semiarido brasileiro, por isso tem contribuido para o desenvolvimento socioeconomico desta regiao. Objetivou-se avaliar a resposta da palma forrageira 'Gigante' cultivada em diferentes densidades populacionais em arranjo mecanizavel. O delineamento experimental utilizado foi em blocos casualizados, com seis densidades populacionais: 22.857; 34.286; 51.428; 62.857; 80.000 e 95.000 plantas haA e quatro repeticoes. Foram avaliadas as seguintes variaveis: altura da planta, numero de cladodios, comprimento, largura e indice de area do cladodio, producao de massa verde e seca, extracao/exportacao de nutrientes e as caracteristicas quimicas do solo. O aumento da densidade populacional em arranjo mecanizavel diminui o numero de cladodios e aumenta o indice de area do cladodio. A maxima producao de massa verde e seca da palma cultivada em arranjo que permite a mecanizacao e estimada quando se utiliza respectivamente a populacao de 69.111,79 e 64.445,91 plantas [hg-1]. Valores maximos de extracao/exportacao de nutrientes em tecido de palma sao estimados em densidades populacionais intermediarias (62.721,52-74.741