The experiment was conducted in a private nursery (Mohammed Nursery) located on Erbil Road in Kirkuk, situated at 44.38°E longitude and 35.58°N latitude. The experiment lasted five months from 01/04/2022 to 01/10/2022 to study the effects of shading with two levels: 0% (under direct sunlight) and 75% (under saran cover), as well as the effect of organic fertilizer (vermicompost) at two levels: 0% and 25%, where the fertilizer was added and mixed with loamy soil. The experiment was conducted using a completely randomized block design. The plants were randomly arranged on the experimental units with three replicates. Duncan's multiple range test was used to compare the means at a probability level of 0.05%.
The results indicated that the 75% shading had a significant effect on some characteristics, such as plant height, dry leaf weight, and leaf area, which reached (82.27 cm), (12.14 g), and (3086.10 cm²) respectively. On the other hand, plants grown under direct sunlight showed a significant increase only in stem diameter (10.69 mm).
Regarding the effect of organic fertilization, a significant increase was observed with the use of 25% vermicompost on the following characteristics: plant height (73.55 cm), dry weight (12.63 g), and chlorophyll content in leaves (29.24 CCI).
It was also found that the use of chelated iron had a significant effect on most characteristics, where the concentration of 0.2 g.L⁻¹ resulted in the highest significant increase in plant height (75.00 cm), main stem diameter (10.37 mm), dry weight (15.35 g), and chlorophyll content in leaves (29.10 CCI).