Humic acid and vermicompost increased bioactive components, antioxidant activity and herb yield of Chicory (Cichorium intybus L.)

Chicory (Cichorium intybus L.) is one of the most important plants in the medicinal, nutritional and cosmetic industry. This study was conducted to evaluate the effects of humic acid (HA) and vermicompost on the herb yield and phenolic components of chicory aerial parts. Plants were grown under 4 humic acid treatments (0, 0.3, 0.6 and 0.9 kg/ hectare) and 4 vermicompost levels (0, 5, 7.5 and 10 t/ hectare) with three replications. Measurement of traits included fresh and dry yields of aerial parts, the IC50 and inhibition percentage of free radicals, the total and individual amounts of phenolics and flavonoids (caffeic, gallic, ellagic and p- coumaric acid, catechin, flavones and flavonols). Results show that humic acid and vermicompost improve the chicory yield and phytochemical properties such as the total contents of phenolics and flavonoids. The highest yield of dry aerial parts (20.29 g per plant) was achieved by 0.9 kg per hectare humic acid in combination with 10 t per hectare vermicompost. The highest total contents of phenolics and flavonoids were achieved when humic acid was applied at 0.9 kg/hectare in addition to vermicompost at 7.5 t/ hectare. The content of caffeic acid was highest among other phenolic components. The highest caffeic acid was achieved by treatments of 0.3 kg per hectare humic acid combined with 5 t per hectare vermicompost. The content of ellagic acid in shoots was highest when vermicompost was applied alone, by 5 t per hectare, with an average yield of 262.51 mg/100 g DW.