Adubação de orquídeas em substratos com fibra de coco

Abstract

The research objective was to evaluate the efficiency of substrates and fertilization levels on the growth and leaf nutrient contents of orchid hybrids of the genus Phalaenopsis. The study consisted of two experiments in carried out with industrialized coconut fiber (Sub 1) and non-industrialized coconut fiber (Sub 2), in mixture with Pinus bark and grade zero gravel (1:1:1 v/v/v) in randomized blocks. The first experiment in a split-plot scheme in time (6 and 12 months) with five replications, evaluated the hybrid RJ 343, in both substrates, under four levels of mineral fertilizer (0; 0.9; 1.2; 1.5 g L-1) and two additional treatments [leaf application of Aminon® (0.5 ml L-1) at 1.2 g L-1, in Sub1 and Sub 2]. The second one evaluated the hybrid RJ 84-2, in both substrates, with the same mineral fertilizer levels and leaf application of Aminon® (0 e 0.5 ml L-1), in a split-split-split plot scheme in time (6 and 12 months) with three replications. The number of leaves, leaf area, superficial root area, leaf, root and total dry weight, and N, P and K leaf contents were evaluated. Aminon® had no effect on the growth of the hybrids. Increase in fertilization led to increased growth, except for roots, with greater growth being observed at 1.5 g L-1 of mineral fertilizer. The Sub 2 caused greater growth of plants of the hybrid RJ 343, whereas the Sub 1 led to greater growth of the hybrid RJ 84-2.