GA 2017

Calendula is cultivated in Brazil and widely used for medicinal purposes due to its healing, anti-inflammatory and antiseptic properties. Brazilian market does not provide vegetal drugs with biomarkers, within recommended range, thus, it is essential to study suitable technologies to produce high quantity and quality of vegetable raw. This work aimed to determinate the phenolic compound content in orange and yellow marigold flowers cultivated with increasing doses of cattle manure. The experiment was conducted at EPAMIG, Minas Gerais, Brazil. Marigold was cultivated in organic system using five doses of cattle manure (0; 30; 60; 90; 120t ha-1). Flowers were harvested, dried in air circulating oven (40°C) and macerated in ethanol. The ethanol was evaporated (40°C) to obtain the crude extracts. The phenolic compounds were determinate by spectrophotometry (760 nm). Crude extracts (5mg) were diluted in ethanol PA (1000μL), where, 200μL were added to Folin-Ciocalteu reagent (1000μL) and 7.5% Na2CO3 (1600μL). The gallic acid was used in the standard curve and the results were expressed in mg/g. The mean contents of phenolic compounds were 679.20±173.65mg/g (CV=9.67%). Higher concentrations of phenolic compounds (931.87mg/g) were found in orange flowers without fertilization (0 tha-1) and lower (368.53mg/g) in yellow flowers fertilized with the highest dose of manure (120 tha-1). In orange and yellow flowers extracts, treatments with fertilization of 30t.ha-1 and without fertilization had higher levels of phenolic compounds. Possibly, these compounds were produced in response to stress and adaptive need to the cultivation conditions. The dose-response curve was inversely proportional to manure doses in all treatments. Yellow flowers and high doses of manure (90 and 120t.ha-1) do not increase the production of phenolic compounds.