Calendula officinalis was experimentally grown under field conditions with different fertilization types and mulching in order to evaluate inflorescence production, plant drugs and flavonoid levels. Experimental design was in randomized blocks, with 3 replicates, in a 3x2 factorial arrangement, consisting of six treatments, as follows: 1. chemical fertilization (100 kg N ha-1 + 50 kg P ha-1); 2. chemical fertilization + mulch (dry grass - Paspalum notatum); 3. organic fertilization (cured bovine manure 50 t ha-1); 4. organic fertilization + mulch; 5. no chemical or organic fertilization + mulch; 6. no chemical or organic fertilization and no mulch (control). Data regarding number of produced capitula, dry matter of inflorescences and plant drug matter were totaled after five months of planting. Flavonoids were quantified by spectrophotometry. The results were statistically analyzed (ANOVA / Tukey-Kramer test-5%) and showed significant differences (70% higher) for number of inflorescences, inflorescence dry matter and plant drug matter between the treatment with organic fertilization (3) and treatments with no chemical or organic fertilization with mulching (5) and control (6). The remaining comparisons, including flavonoid content, did not result in significant differences among treatments.
Calendula officinalis; flavonoids; fertilization; mulching
