Photosynthesis and Antioxidative Systems of Andrographis paniculata as Affected by Compost Tea Rates

Andrographis paniculata (Burm.f.) Nees is a medicinal herb in the family Acanthaceae. The leaves of the mature plant contain abundant diterpinoids of medicinal properties.The objectives of the present study were to investigate the impacts of compost tea rates on photosynthesis parameters and antioxidant reactions of A. paniculata. The plant was propagated using seed and planting in a polybag. After four weeks, the plant was transplanted into polybag sized 20 cm×25 cm. Compost tea was used at rates of (0, 25, 50, 75 and 100%). Treatments were arranged in randomized completely block design (RCBD) with three replicates. Before flowering stage, the plants were harvested. The results revealed that rates of compost tea significantly affected total dry weight, leaf area, chlorophyll, stomatal conductance, FRAP and total flavonoid contents (P≤0.01), while there were no significant difference on DPPH reduction, and total phenolic contents and photosynthetic rate. Soil amendment with compost tea gave a favorable effect on growth and improved soil pH and CEC. Total flavonoid was highly significantly differences among the treatments. The greatest TDW (26.15 g), FRAP (96.03% of inhibition) and flavonoid (1943.7 mg/g) were observed at the 70% rate of compost tea. The highest rates of compost tea (100%) significantly decreased the phenolic and flavonoid compounds. These results suggested that A. paniculata could reach high biomass and quality characteristics with 50 and 70% rate of compost tea. However, in general compost tea had a good potential to improve soil pH and increase plant growth and antioxidant contents.