| here are more than 300 species of hibiscus found around the world. Only roselle hibiscus (Hibiscus sabdariffa) provides the swollen red calyces and is used in herbal tea and other food products due to its antioxidant activities and medicinal properties. A field experiment was conducted to evaluate the effects of both organic and inorganic fertilizers on the nutrient elemental content of the calyces, as well as their total polyphenol and antioxidant contents of the calyces. Data indicated that organic 4-2-2 fertilizer applied at planting time had no significant effects (P<0.05) on the elemental content of N,P, K, Mg, S , B, Cu, Fe and Zn. Pelletized organic 8-5-5 fertilizer also had no significant effects (P<0.05) on the elemental content of N, P, K, Mg, S, B, Cu and Fe. Pelletized organic 8-5-5 also had fertilizer significantly (P<0.05) increased Mn content but significantly (P<0.05) reduced Ca and Zn content. The application of inorganic 13-13-13 fertilizer had no significant effects on N, P, K, Ca, Mg, S, B, Cu and Fe. Transversely, the inorganic fertilizer at 6... |
