Produção de mudas de Guazuma ulmifolia sob aplicação de tiamina

Abstract

Obtaining seedlings with high morphophysiological quality affects the survival and development of plants after transplanting. In this way, new techniques must be constantly elaborated in order to obtain the best results in the field. The objective of this study was to evaluate the morphophysiological responses of three lots of G. ulmifolia seedlings at different doses of thiamine, applied on the substrate. Three experiments were carried out, represented by three lots of seedlings (emerged at the 2nd, 4th and 6th weeks after sowing), showing uniformity of development among themselves. A completely randomized experimental design (DIC) was used, with five replicates, each replicate was composed of a black polyethylene pot with a volume of 300 cm3, containing one plant. Five treatments, which were defined by the thiamine dose (0, 5, 10, 15 and 20 mg plant-1), were applied at the moment after transplanting of the emerged seedlings into the pots, by application on substrate. At 45 days after transplanting the seedlings to the pots, the relative content of chlorophyll a, b and total, height, total leaf area per plant, number of leaves, average leaf area, dry shoot weight and root shoot weight. It was verified that the application of thiamine at increasing doses up to 11.25 mg plant-1 promotes gains of the characteristics of total leaf area, number of leaves, height and dry mass of shoots of Guazuma ulmifolia Lam. with a more pronounced effect on plants with greater vigor.