Mineral nutrition of sesame plants (Sesamum indicum L.): II - concentration and accumulation of micronutrients under field conditions

Abstract

A field experiment was set in Piracicaba (SL:22º41'31" and LW: 47º38'01") , State of São Paulo, Brazil, in a soil classified as "Terra Roxa Estruturada (AJfissol), Série Luiz de Queiroz", in order to study: the concentration of micronutrients in the different plant organs; the accumulation of micronutrients by the whole plant and the exportation of micronutrients through the pods. Plants (4 replications) with 28, 40, 52, 64, 76, 88, 100, and 120 days from emergence were collected and divided into leaves, stems and pods. The material was dried at 80ºC and analysed for some micronutrients. The results were as follows: the accumulation of micronutrients was always higher in the leaves than in the stems, except for Zn; the total accumulation of micronutrients by the whole plant increased with aging until 112 days, except for B in the leaves and B and Fe in the stems; the accumulation of micronutrients (mg) at the final growth stage was: Fe(134.42) Mn(2l64) Zn(l054) B (8.01) Cu(3-81); the concentration of micronutrients in the leaves, stems and pods occurred in the following order: Leaves: Fe(772 ppm) >; Mn(311 ppm) >; N (117 ppm) >; B (95 ppm) >; Cu(23 ppm). Stems: Fe(528.08 ppm) >; Mn(148.41 ppm) >; B(72.28 ppm) >; Zn (65.09 ppm) >; Cu (15.89 ppm). Pods: Fe(282.24 ppm) >; B(41.Q4 ppm) >; Mn(30.87ppm) >; Zn(22.04 ppm) >; Cu(l6.33 ppm).