GGE Biplot as a Novel Tool for the Investigation of Marigold (Tagetes erecta L.) Seedling Growth on Composted Corn Stalk as a Substrate

This project investigated the feasibility of using ground corn stalks as the substrate to cultivate marigold (Tagetes erecta L.). Five treatments including peat moss, composted corn stalks and freshly ground corn stalks were tested for their effects on marigold seedling growth. Seedling quality was described by several morphological and physiological parameters. Data were analyzed using analysis of variance and GGE biplot analysis. There were significant differences among the treatments for several growth parameters, such as seedling biomass, root biomass, stem diameter, leaf area, seedling vigor, chlorophyll content, photosynthetic rate, root activity, stomatal conductance, and intercellular CO₂ concentration. Treatment T3, which contained composted ground corn stalks, had the best effect on marigold seedling growth. The results showed that corn stalk was a good substrate for marigold seedlings. GGE biplot demonstrated the substrate effects on marigold seedling quality, and graphically displayed the interrelationships among morphological and physiological parameters. T3 treatment was the best because four morphological parameters, including seedling biomass, roots biomass, stem diameter and seedling vigor, along with six physiological parameters fall into this sector. These results were consistent with the results analyzed by Statistical Analysis Software. For morphological parameters, the correlations are complicated. For physiological parameters, they were all positively correlated between each of two parameters.