Deficiência de macronutrientes e de boro em abacaxizeiro 'Imperial': composição mineral

This study was carried out to evaluate the effects of macronutrients and boron deficiencies in 'Imperial' pineapple on the leaf concentrations of those nutrients. The treatments Complete, -N, -P; -K, -Ca, -Mg, -S and -B were applied as nutrient solutions, to plastic pots filled with 14kg of purified beach sand and one pineapple seedling, as the experimental unit, in a randomized complete block design with six replicates. The "D" leaf concentrations of N, P, K, Ca, Mg, S and B were determined at five, seven, nine and twelve months after the planting. The deficiency of N reduced the absorption of S, but it increased the concentrations of P, K, Mg and B; that of P reduced N, Ca, Mg, S and B concentrations, but it increased that of K; that of K increased N, P, Ca, Mg, S and B concentrations; that of Ca increased K and Mg concentrations and reduced the one of S; that of Mg and of B increased Ca concentration and that of S increased K and B concentrations. The leaf concentrations of the normal and deficient plants at the beginning of fruit growth were, respectively: N = 14.8 and 9.7; P = 1.23 and 0.67; K = 20.0 and 11.6; Ca: 4.37 and 0.91; Mg = 2.26 and 0.73; S = 1.45 and 0.45 g kg(-1) and B = 18.4 and 5.8 mg kg(-1).