The aim of this work was to study the growth, development and production of burdock in response to five spacing levels among plants (40.0; 47.5; 55.0; 62.5; and 70.0 cm) and to the use (CCF) or not (SCF) of soil covering with semi-decomposed poultry litter. Experimental design was in randomized blocks, with four replicates, in a 5x2 factorial arrangement, with ten treatments. Plants were initially propagated in polystyrene plates; then, they were placed in flower beds and displayed in double rows, with 0.50m spacing between simple rows and 1.0m between double rows. Height was evaluated from 30 to 180 days, when harvest was performed. Mean height (172 cm), leaf area (20,704 cm²), root length (23.6 cm) and diameter (16.2 mm) were not significantly influenced by spacing or soil covering. The highest and lowest values of leaf fresh (25,676 kg ha-1 and 15,217 kg ha-1) and dry matter (1,941.02 kg ha-1 and 1,104.61 kg ha-1), root number (490,750 ha-1and 272,120 ha-1) and fresh (5,080.35 kg ha-1 and 3,546.25 kg ha-1) and dry matter (1,448.91 kg ha-1 and 1,051.31 kg ha-1) were obtained at 40.0 and 70.0cm spacing between plants, respectively, which shows a linear decrease with spacing increase. Nitrogen (N) and phosphorous (P) levels, in dry matter of leaves (12.84 g kg-1 and 0.33 g kg-1) and roots (4.11 g kg-1 and 0.13 g kg-1) of burdock, respectively, were not significantly influenced by spacing but by soil covering with poultry litter.
medicinal plants; plant population; organic residue
