Colored shade nets and foliar ProLyks<sup>®</sup> application modulate plant growth and secondary metabolism in Mikania laevigata Sch. Bip. ex-Baker

The efficacy and safety of phytotherapeutic medicines are intrinsically related to the quality of their plant-based raw materials, which is directly influenced by agronomic cultivation practices. The objective of this study was to evaluate the effects of colored shade nets and foliar application of ProLyks® on the growth and secondary metabolism of Mikania laevigata Sch. Bip. ex-Baker. The experiment followed a completely randomized 4 × 5 split-plot design, with three photoselective shade nets (red, blue, and black) compared to full sunlight (control) and five ProLyks® doses (0.00, 0.25, 0.50, 1.00, and 2.00 mL·L⁻¹). Significant interactions between these factors were observed for plant height, number of leaves, leaf dry matter, and coumarin content. The red net promoted the highest biomass production and, when combined with the 1.5 mL·L⁻¹ ProLyks® dose, also maximized coumarin accumulation in leaves, indicating a possible elicitor effect under these conditions. A considerable positive correlation between plant height and coumarin content suggests that taller plants may serve as a practical field indicator of superior pharmaceutical quality. Additionally, an inverse correlation between total chlorophyll and flavonoid content highlights a trade-off between photosynthetic pigment synthesis and secondary metabolism. These findings demonstrate that red shade nets combined with the optimal ProLyks® dosage can enhance both biomass yield and phytochemical production in M. laevigata, while also providing useful indicators for field selection of high-quality materials for the national pharmaceutical industry.