This study was conducted in the wooden greenhouse of the Department of Horticulture and Landscape gardening, college of Agriculture, Tikrit University, to investigate the effect of foliar spraying with garlic and licorice extracts on the growth and flowering of chrysanthemum plants. The experiment was conducted according to a randomized complete block design (RCBD) with two factors: garlic extract concentrations and licorice extract concentrations, in addition to studying the effect of the interaction between them on many vegetative, floral, and physiological characteristics of the plant.
The results showed that G3L3 significantly outperformed all other treatments in all features studied. The highest plant height (20.70 cm), highest number of leaves (24.96 plant leaves⁻¹), largest flower diameter (7.96 mm), largest flower weight (4.36 g), and highest chlorophyll content (35.73 SPAD) were recorded compared to the remaining treatments.
This superiority can be attributed to the positive effect of the bioactive compounds and nutrients present in garlic extract, as well as the active ingredients of licorice extract, such as glycyrrhizin and flavonoids, which stimulate cell division, improve vegetative and floral growth, and enhance the physiological efficiency of the plant. The results also showed a synergistic effect between the two extracts, improving photosynthesis processes as well as promoting the growth and flowering of chrysanthemum plants.