Physiological and morphological responses of seedlings of Guazuma ulmifolia (Malvaceae) grown under phosphorus levels

Abstract Phosphorus (P) is one of the nutrients most required by plants, especially in the initial phase, however, there are species whose growth effects promoted by phosphorus are still unknown. Therefore, this study aimed to test whether increasing levels of phosphorus influence the physiological and morphological behavior and the quality of seedlings of Guazuma ulmifolia. For that purpose, the seedlings were grown in a substrate produced only with Dystrophic RED LATOSOL (Oxisol) under a completely randomized design and subjected to five levels of phosphorus (0, 100, 200, 300, and 400 mg dm-3 ). At 120 days, the biometric and physiological evaluations were performed, and the chlorophyll indices, biomass, allometric relationships, Dickson Quality Index, and the phosphorus content were determined. The data were subjected to analysis of variance by the F-test and subsequently to regression analysis and Pearson’s linear correlation. Phosphorus fertilization promoted significant gains (p ? 0.05) for all variables morphological e physiological, except for the specific leaf area and allometric relationships. The phosphorus content was positively correlated with all tested variables. Based on the results obtained, it is concluded that the seedlings responded positively to phosphorus fertilization. Furthermore, phosphorus fertilization promoted better physiological and morphological performance and higher seedling quality.