Effect of Water Limitation on Gynura procumbens Growth and Phytochemıcal Content

Abstract

The cultivation of Gynura procumbens holds immense value due to its pharmaceutical and therapeutic properties. A critical factor in its cultivation involves understanding how water availability impacts its biomass production and phytochemical profile. Water stress generally induces physiological changes in plants, such as reduced growth and increased production of secondary metabolites as a survival strategy. Under water-limited conditions, plants prioritize essential functions, including maintaining cellular integrity, often at the expense of biomass accumulation, which subsequently influences the phytochemical composition of G. procumbens. This study aimed to investigate the effects of water limitation before harvest on the biomass and phytochemical content of G. procumbens, providing insights into its adaptive response to water stress. Water limitation treatments were applied for varying durations before harvest: T1 (no water limitation), T2 (4 days), T3 (7 days), and T4 (15 days). The experiment followed a Randomized Complete Block Design (RCBD) with four replications. After a 60-day cultivation period, plant growth, biomass, total phenolic content (TPC), chlorogenic acid levels, and antioxidant activity were assessed. The findings revealed that water limitation from 4 to 15 days before harvesting led to reduced growth and biomass, with more extended periods causing greater adverse effects. Notably, the T4 treatment (15 days of water limitation) resulted in the highest TPC, while T2 (4 days of water limitation) optimized chlorogenic acid production. Both T2 and T4 treatments demonstrated enhanced antioxidant activity, linked to chlorogenic acid and TPC levels, respectively. This study highlights that increasing the duration of water limitation before harvest significantly affects both the biomass and phytochemical composition of G. procumbens.