Efeito da substância húmica na germinação de sementes de Myracrodruon urundeuva Fr. All.

Humic substances are originated from the oxidation and polymerization of the organic matter, with high molecular weights and diverse functional groups. Depending of the solubility aqueous environment humic substances are divided in humic acid, fulvic acid and humin. There are few researches related to the humic substances effects on seeds germination, and were not found researches using species Myracrodruon urundeuva Fr. A11. Humic substances compositions are varied that makes it hard to understand its effects. The work intended to analyse the effects of different concentrations of humic substances on Myracrodruon urundeuva Fr. All seed germination. The work was developed in the seed laboratory in the Federal University of Tocantins, where the seeds were kept emerged for 12 hours within a solution containing 0.00; 0.25; 0.50; 0.75 and 1.00% of humic substance concentration, were subsequently germinated in B.O.D regulated at 25 °C. These samples have been evaluated by percentage measures, average time and germination speed index. Humic substances application in concentration 0 and 0.25% might provide positive effect on germination and on Myracrodruon urundeuva Fr. All. seeds germination speed index and higher concentrations cause phytotoxic effect. [ABSTRACT FROM AUTHOR]