MACROPHYTES AS SOURCE OF NUTRIENTS ON INITIAL GROWTH OF SUNFLOWER PLANTS

Resumo

The present study assessed the initial growth of sunflower seedlings under different concentrations and species of macrophytes, verifying the viability of their use as source of nutrients. Biometric and vigour variables were assessed through measurements of stem diameter, height of aerial part, number of leaves, relative chlorophyll contents and production of dry matter from roots and shoots. The experimental design was entirely randomized with 4 different materials for substrate composition: Salvinia auriculata, Thalia geniculata, Cyperus auriculatus and mixed macrophyte compost, and the following concentrations of macrophyte nitrogen in the substrates: 40, 80 and 120 kg N ha^-1. Pots containing only sand and pots with sand and commercial worm humus at 80 kg N ha^-1 were used as control treatments. The collections were performed at 14 and 21 Days After Sowing (DAS), containing eight repetitions with three plants each. The averages obtained at 14 and 21 DAS were compared by Tukey's test (P ≤ 0.05) through the statistical program Sisvar 5.6. It was found that the use of macrophytes promoted increases in the variables analyzed, however, the best results were provided by the treatment Salvinia sp. at 120 kg N ha^-1.