Effects of GA₃ concentrations on nursery performance and the development of seedling quality standards for seed-propagated Stemona tuberosa Lour.

Abstract

This study investigates the effects of GA₃ concentrations on seed germination and nursery performance, and establishes seedling quality standards for seed-propagated Stemona tuberosa Lour. Seeds were subjected to four treatments: distilled water (control) and GA₃ solutions at 5, 10, and 15 ppm. Treatment with 5 ppm GA₃ produced the highest germination rate (61.0%) and nursery-ready seedling rate (60.3%). Seedlings in this treatment exhibited increased plant height and shoot number relative to the control, whereas leaf number and root development showed no statistically significant differences. Seedling quality was further assessed across five transplanting ages—90, 105, 120, 135, and 150 days and plant survival and early field growth were evaluated 60 days after transplanting. The results identified 120-day-old seedlings as the optimal age for field establishment. These seedlings demonstrated consistent and robust performance, with the following characteristics: an average of 2 shoots, a plant height of 10.80 cm, 5.67 true leaves, a stem diameter of 2.11 mm, 3.67 primary tuberous roots, an average root length of 5.1 cm, and a root diameter of 4.25 cm. Overall, the findings provide a solid empirical basis for enhancing seed-based propagation practices and standardizing seedling quality for S. tuberosa cultivation.