Nutrient omission effect on growth and nutritional status of assai palm seedlings

Abstract

The Amazonian assai palm has a great socioeconomic importance, but most of its commercial plantations take place in uplands and low natural fertility soils, what may hinder its development. This study aimed at evaluating the effect of nutrient omission on growth and nutritional status of assai palm seedlings (Ver-o-Peso cultivar). The experimental design was completely randomized, with 14 treatments and 5 replicates. The treatments consisted of complete fertilization with liming; no fertilization and no liming (control); complete fertilization with individual omission of N, P, K, Ca, Ca with no liming, Mg, Mg with no liming, S, B, Cu and Zn. Plant height, stem diameter and dry mass, leaf and total shoot dry mass, and leaf nutrients content and accumulation were evaluated. The initial growth of the assai palm plants was limited by the omission of P, N, K, Ca, Mg and Cu. The production of leaf dry mass was decreasingly affected by the omission of P > Cu > N > K > Mg, while leaf area was limited by the individual omissions of Ca > N > P > K > Mg > Zn. Plant development, measured by relative growth of shoots, was affected by lack of Ca > P > N > Mg > Cu > K, with an average reduction of 31 %. The nutrients most needed by the assai palm plants, as evidenced by nutrients contents and accumulation in the leaf dry mass, are: N > K > S > Ca > Mg > P > Mn > Zn > B > Cu.