Enhancing Gardenia Leaf Nutrients via Shading, Vermicompost and Chelated Iron

Abstract

This study aimed to investigate the impact of shading, vermicompost, and chelated iron on the leaf content of certain elements in Gardenia jasminoides plants. Conducted at a private nursery in Erbil during the 2022 agricultural season, the experiment utilized gardenia plants propagated by cuttings and grafted onto one-year-old rootstocks. Over five months (April to October 2022), the effects of two shading levels (0% and 75% direct sunlight), vermicompost application at two levels, and chelated iron application at three levels (0, 0.1, and 0.2 g.L-1) were assessed. Results indicated that 75% shading significantly increased leaf nitrogen (1.72%) and iron content (73.94 mg.kg-1). Vermicompost at 25% significantly enhanced leaf nitrogen (1.75%), phosphorus (0.248%), potassium (1.36%), and iron (67.95 mg.kg-1). Chelated iron at 0.2 g.L-1 markedly improved leaf nitrogen (1.78%), phosphorus (0.256%), potassium (1.28%), and iron (78.45 mg.kg-1). The study utilized one-year-old uniform seedlings, grown in 15-liter pots with river loam soil, and standard care practices were followed. Data analysis was performed using ANOVA and Duncan’s Multiple Range Test at a 0.05 significance level. The findings suggest that specific shading, organic fertilizer, and chelated iron treatments can significantly enhance the nutrient content of gardenia leaves, potentially improving plant health and growth.