Do Stimulate® and Ascophyllum nodosum seaweed promote the morphophysiological characteristics of Cordia alliodora seedlings?

Abstract

Biostimulants in native forest seedlings, when absorbed and assimilated by plants, can function as activators or inhibitors of their metabolic and physiological processes. In view of the above, the present study establishes the following research problem: Can doses of Ascophyllum nodosum seaweed extract and Stimulate® be effective in the promotion of initial growth and morphophysiological indices of Cordia alliodora seedlings? The experimental design used was completely randomized, in a 4 x 2 factorial scheme, corresponding to four doses (0, 0.2, 0.4 and 0.6 ml L-1) and two hormones (Ascophyllum nodosum and Stimulate®), with five replicates, each of which composed of five seedlings (one in each container). The morphological variables evaluated were shoot height (H), stem diameter (SD), increments in stem diameter (ΔSD) and shoot height (ΔH), shoot dry mass (SDM, g plant-1), root dry mass (RDM, g plant-1), total dry mass (TDM, g plant-1), and Dickson Quality Index (DQI). Physiological variables were: net assimilation rate (EA, g.m-2.day-1), leaf relative growth rate (RA, g.m-2.day-1), leaf area ratio (FA, m2.g-1), specific leaf area (SA, cm2.g-1) and leaf mass ratio (Fw, g.g-1). The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 promotes increments in height (ΔH) and stem diameter (ΔSD) of Cordia alliodora seedlings. Ascophyllum nodosum at dose of 0.2 ml L-1 has positive influence on the physiological indices studied in Cordia alliodora seedlings at 120 days after transplanting. The bioregulator Stimulate® at dose of 0.6 ml L-1 is not indicated to obtain Cordia alliodora seedlings with better quality and sturdiness and shorter nursery time. The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 is recommended to obtain increments in height (ΔH) and stem diameter (ΔSD) in Cordia alliodora seedlings