Vegetative growth of neem seedlings (Azadirachta indica L.) as affected by kinetin, arginine, and chelated iron

Abstract

A pot experiment was carried out in the canopy of the Horticulture and Landscape Department - College of Agriculture - University of Kerbala For the period from July 2023 to June 2024. The study was carried out as a factorial experiment with three replications in a randomized complete block design to study the effect of kinetin (0, 50, and 100 mg L^-1) (K0, K1, K2, respectively), and arginine (0, 150, and 300 mg L^-1) (A0, A1, A2, respectively), and chelated iron (0 and 200 mg L^-1) (Fe1, Fe2, respectively) in the vegetative growth of neem seedlings. The results showed the varying effect of adding the study factors individually, as kinetin had a significant effect on most of the vegetative traits under study, while adding arginine had no significant effect on most of the vegetative traits, except for stem diameter, which was significantly affected, while chelated iron had a significant effect on leaf area and plant height. The results of the binary interaction varied between the study factors on the studied traits. The triple intervention had a significant effect on the plant height, as the treatment (Fe2K2A2) gave the highest rate of plant height, reaching (46.00 cm), and the highest rate of stem diameter, reaching (6.337 mm), While the treatment (Fe1K2A2) gave the highest average leaf area, reaching (1123 cm²). It can be concluded from this study that spraying arginine with chelated iron had an effective role in improving the early vegetative growth of seedlings, but the use of high concentrations of kinetin must be taken into account, as the results reflected the negative effects of high concentrations on most of the traits studied.