Abstract

The study was conducted during the period from( 2023/4/1) to(2024/4/1). using the plastic greenhouse of the College of Agriculture and Forestry / University of Mosul. to evaluate the efficiency of Nano Fe and GA3 acid by spraying on the Brachychiton populneus. he spraying process was conducted using two factors: the first factor was Nano Fe fertilizer at four concentrations (0, 1, 3, 5) mg.L-1 and the second factor was GA3 acid at four concentrations (0, 250, 500, 750) g.L-1. The seedlings were arranged using a completely randomized design with three replications, where each replication contained 16 treatments, and each treatment included 5 seedlings. the results showed that seedlings treated with Nano Fe at a rate of 3 g.L-1 had significantly outperformed in several growth traits. These included an increase in stem diameter growth by 15.891mm. seedling-1, an increase in the number of vegetative branches by 2.072 branches. Seedling-1and an increase in the dry weight of the vegetative mass by 24.515 g. Additionally, spraying with GA3 at a concentration at a rate of 500 mg. L-1 had a significant effect, with seedlings showing an increase in stem diameter growth by 13.539 mm. Seedling-1and an increase in the dry weight of the vegetative mass by 20.095 g. On the other hand the interaction between Nano Fe at a concentration at a rate of 3g. L-1 and GA3 acid at a rate of 500 mg. L-1 was a significant effect, with seedlings showing an increase in stem diameter growth by 18.630 mm. Seedling-1 and an increase in the dry weight of the vegetative mass by 27.110 g. Furthermore, the results showed that the interaction between spraying with 5 g. L-1 Nano Fe and 500 mg. L-1 of GA3 acid had a significant effect on increasing stomatal density, which reached 0.107 stoma.mm-2.