Effect of different levels of nutrient on productivity, and diterpene lactone content of Kalmegh [Andrographis paniculata (Burm. f.) Wall. ex Nees]

An investigation was conducted at the research farm in Doddabalapura, India, during the years 2023–24 to examine the impact of varying nutrient levels on the productivity and diterpene lactone content of Kalmegh [Andrographis paniculata (Burm. f.) Wall. ex Nees]. The findings indicated that significant increases in plant height (51.41 cm), branches per plant (24.43), fresh herb yield per hectare (9212.93 kg), and dry herb yield per hectare (2982.70 kg) were achieved with the application of 100% Poultry manure + 2% AMC (T4), comparable to (T8) 50% Poultry manure + 50% FYM + 50% Neem cake + 2% AMC + 3% Panchagavya at 125 DAS. Moreover, the highest levels of total andrographolide (2.89%) and total diterpene lactone content (3.01%) were observed in treatment (T7), which involved the application of 50% Vermicompost, 50% Neem cake, 2% AMC, and 3% Panchagavya, at 85 days after sowing, similar to treatment (T6) 50% FYM + 50% Neem cake + 2% AMC + 3% Panchagavya, when compared to the control group.