Effect of Organic Fertilization with Humic Acid and Foliar Spraying with Bread Yeast Extract on the Growth and Yield of the Solanum Melongena L

A pot experiment was conducted in one of the orchards in Al Salam district at the Diyala governorate during the 2021 agricultural season. The purpose is to investigate the effect of Humic acid and Saccharomyces cerevisiae (bread yeast) on the growth and productivity of the Solanum melongena L plant (eggplant). The study involved plant watering with three concentrations (0, 2, and 4 g.l-1) of Humic acid, and leaves spraying with three concentrations of bread yeast (0, 5 and 10 g.l-1). The study also investigates the synergistic effect between the two additives on the growth and productivity of the plant. The experiment was conducted according to a completely randomized design (CRD) with three replications. The results revealed significant improvement (5%) in the vegetative characteristics and yield trait due to the watering with Humic acid (2, and 4 g.l-1), and the best obtained average improvement was at Humic acid concentration of 4 g.l-1. The results, also, indicated significant development in all the studied traits due to the spraying with bread yeast at concentrations 5 and 10 g.l-1. The best achieved averages were due to the spraying with the higher yeast concentration (10 g.l-1). Moreover, combination that consists of 4 g.l-1 Humic acid + 10 g.l-1 bread yeast (H 4 g.l-1 + Y 10 g.l-1) yielded the highest averages for all studied traits except the fruit diameter where the combination (H 4 gl-1 + Y 5 gl-1) developed the highest averages. However, the lowest averages were obtained from the control combination (Y 0 g.l-1 + H 0 g.l-1).