Assessment of nutrient requirement for fertilizer recommendation in Kariyat (Andrographis paniculata)

Abstract

Kariyat (Andrographis paniculata) is a medicinal plant recognized for its therapeutic potential during the COVID-19 pandemic due to the presence of andrographolide, an active compound with antiviral properties effective against the causative virus. However, variations in fertilizer application may influence plant growth and the accumulation of active constituents. This study aimed to evaluate the nutrient requirements of A. paniculata in order to formulate appropriate fertilizer recommendations. Plants were harvested at 2, 4, 6, 8, 10, and 12 weeks after transplanting into decomposed empty oil palm fruit bunches, which provided sufficient basal nutrients, and were supplemented with a nutrient solution to assess growth performance, nutrient uptake, and andrographolide content. The results indicated that plant height, stem diameter, fresh and dry weights, andrographolide content, and total nutrient uptake of A. paniculata significantly increased (P < 0.05) with extended harvesting periods. The overall uptake ratio of nitrogen, phosphorus, and potassium was 8:1:9, corresponding to an N:P2O5:K2O ratio of 3:1:5 for nutrient absorbed from the soil. Based on these findings, a compound fertilizer formulation of 15–5–25 applied at a rate of 178 kg/rai is recommended. For acidic soils with low calcium and magnesium levels, dolomite should be applied at 95 kg/rai to ensure adequate nutrient availability for optimal plant growth.