Data Sheet 2_Effects of foliar nitrogen application on morphological and physiological characteristics in newly emerged leaves of Bambusa emeiensis.docx

IntroductionBamboo growth is highly nitrogen-dependent, particularly during the branch and leaf extension phase. Foliar nitrogen application offers a precise and efficient alternative to soil fertilization. However, little is known about its effects on the growth and physiology of developing leaves in bamboos.
MethodsIn this study, different concentrations of urea (1%, 2%, 3%, 4%, and 5%) were applied to the newly emerged leaves of Bambusa emeiensis. Leaf samples were collected at 7, 14, and 21 days after treatment. The effects of foliar urea application on morphological development, sugar metabolism, and oxidative stress responses were assessed.
ResultsThe foliar application of 0.3% urea significantly enhanced leaf development, as evidenced by increased leaf length, width, and thickness. It also boosted the content of photosynthetic pigments and the activities of sugar-metabolizing enzymes, leading to greater photoassimilate accumulation. Concurrently, it elevated the activities of antioxidant enzymes (superoxide dismutase, catalase, and peroxidase), which reduced the levels of hydrogen peroxide and malondialdehyde.
DiscussionThese findings indicate that moderate foliar urea application enhances leaf development and stress tolerance in B. emeiensis by promoting photoassimilate production and antioxidant capacity. This provides a physiological basis for precision nutrient management in bamboo cultivation.