Substrates based on swine wastewater in the production of seedlings of Guazuma ulmifolia (Malvaceae)

Abstract

Swine wastewater (sw) can boost seedling growth and development in several species as this residue is rich in nutrients required by plants. This study tested the hypothesis that seedlings of Guazuma ulmifolia grown in a substrate based on swine wastewater showed better physiological and morphological performance. The seedlings were cultivated in seven substrates: T1 - rice husk and vermiculite; T2 - 20% sw; T3 - 40% sw; T4 - 60% sw; T5 - 80% sw; T6 - 100% sw; and T7 - 100% Bioplant®. Were evaluated the height (H), diameter (D), number of leaves (NF), as well as the H to D ratio, chlorophyll indices, gas exchange, biomass, allometric ratios, Dickson Quality Index (DQI), and mortality percentage of the seedlings. The data were analyzed by analysis of variance, and the means were compared by Tukey’s test. The substrates with the highest percentage of swine sludge promoted the highest H, D, NF, chlorophyll indices, gas exchange, stem biomass and IQD. The highest mortality was obtained in commercial substrate (85%) and carbonized rice husk and vermiculite (37.5%). Can be concluded that the substrates with high swine wastewater content were better for seedling G. ulmifolia.