The cultivation of Mitragyna speciosa (kratom) has gained significant interest due to its diverse alkaloid profile, increasing its commercial and medicinal demand. Using controlled hydroponic techniques, this study investigates the effects of varying light intensity and water potential on kratom growth, mitragynine (MG) accumulation, and total alkaloid content (TAC). While the interaction between light and water potential was generally not significant, water potential emerged as the dominant factor affecting plant growth and alkaloid accumulation. The highest MG accumulation (0.63% w/w) was recorded under moderate water potential (−0.4 MPa). In contrast, the highest TAC (8.37 mg alkaloid equivalent per gram dry weight) was observed under the combined effect of low light and mild water potential (−0.4 MPa). Leaf age also played a key role, with younger leaves (second and third pairs) accumulating significantly higher MG levels (0.74% w/w) than older leaves (0.40% w/w). Additionally, leaf thickness was positively associated with MG levels, suggesting a potential link between plant morphology and alkaloid biosynthesis. However, low water potential (−0.7 MPa) significantly reduced both growth and MG content, highlighting the importance of optimizing environmental conditions for sustained bioactive compound production. These findings demonstrate the physiological adaptability of kratom to variable environmental stresses and their influence on alkaloid accumulation. This knowledge can be applied to precision cultivation strategies to enhance the sustainability of kratom farming while optimizing the production of bioactive compounds for pharmaceutical and agricultural applications.

This study investigates how soil calcium (Ca) and magnesium (Mg) supplementation influence mitragynine accumulation in Mitragyna speciosa (kratom), addressing the lack of quantitative thresholds in previous research. Seedlings from a uniform seed stock were cultivated in a controlled environment using a standardized soil mix (soil:peat moss:earthworm castings, 6:1:1). Following an initial growth phase, Ca and Mg were applied at three concentrations and in fixed Ca:Mg ratios (5:1, 10:1, 20:1) using gypsum and Epsom salt. Over a 45-day treatment period, growth parameters and mitragynine levels were assessed one week after the final application. Seedlings under control had the highest total biomass (102.35 g), significantly exceeding both the Mg-only and Ca:Mg treatments (64–84 g), and values above the typical upper threshold of 20 did not suppress growth, as evidenced by unchanged root-to-shoot ratios across treatments. In contrast, mitragynine accumulation was the highest under moderate Ca:Mg ratios (8–10), exhibiting a 2–14% increase relative to the control, suggesting that production of this alkaloid is more sensitive to nutrient balance than overall growth. These findings underscore the importance of nutrient ratios, rather than individual nutrient concentrations, in regulating both vegetative development and alkaloid production in kratom. Maintaining an appropriate Ca:Mg ratio can support efficient seedling growth as well as maximizing mitragynine levels. Preliminary field trials over a span of one month indicate that field-grown seedlings exhibit a similar result with high growth and mitragynine content in soils having a Ca:Mg ratio of 1:10. Future studies should test these responses under field conditions and over longer growth periods.