Ecofisiologia do crescimento inicial de mudas de morototó (Schefflera morototoni, Aubl. Frodin - Araliaceae) cultivadas sob quatro níveis de radiação solar e três níveis de espaçamento / Antenor Pereira Barbosa.

Dissertação (mestrado)--INPA/UFAM, Manaus, 1985.

To obtain basic information on planting stock quality and growth potential of Morototó (Schefflera morototoni Aubl. Frodin - Araliaceae) seedlings were grown under four solar radiation levels and at three spacing levels. The effect of the treatments on growth and morphological variables of seedlings were measured at 30, 60 e 90 days and analysed in a 4 x 3 factorial design. The air temperature and relative humidity were not modified by solar radiation levels in seedbeds. Solar radiation levels modified light quality. Solar radiation level effects were increasingly high on height of plants, collar diameter and leaf area variable. The spacing levels did not show statistical differences. The distribution of dry matter accumulated followed this increasing order: roots, stems and leaves in all seedlings and all observations. The full light did not keep the same sequential order, because the seedlings lost the leaves at first days. Higher shading levels increased the dry matter of roots, stems, leaves and of the whole plant during the experiment. Mutual shading and accelerated senescence of leaves decreased seedling dry matter production rate under shading. There was a trand toward decrease on net assimilation rate and relative growth rate at the lowest rates. Net assimilation rate and relative growth rate at full light treatment, increased at decreased rates. Leaf area ratio increased under shading by influences of specific leaf area as murch as of leaf weight ratio. Shading increased the growth rate of the studied specie, showing the trend of easy adaptation and potential ability to compete in lower solar radiation enviromental conditions.

Área de concentração: Manejo Florestal.