A field experiment determined the effects of foliar application of zinc (0, 25, and 50 mg Zn L^-1) and manganese (0, 30, and 60 mg Mn L^-1) concentrations on growth variables of three mung bean cultivars (Indian Green VC6089A10, Indian Green VC6173B1319, and Indian Black Gold Star). The study commenced in the crop season 2022 at the College of Agriculture, District Ramadi, Anbar Governorate, Iraq. The experimentation followed a randomized complete block design with a split plot arrangement. The zinc levels showed significant differences for growth traits, and the 50 mg Zn L^-1 level exhibited the highest average characteristic for the vascular bundle thickness (232.1 μ). However, the manganese (60 mg Mn L^-1) exceeded the measurement of the lower stomata width (13.50 μ), and its comparative treatment (15.74 μ) outperformed the rest of the variants. The mung bean genotype Black Indian outshone the rest of the cultivars for most traits, such as lower stomata length (16.29 μ), but it did not differ significantly from the cultivar Green Vc6089a10 for the mentioned trait. The interactions of foliar application of zinc, manganese, and mung bean cultivars significantly influenced all these growth parameters.

Keywords: Mung bean (Vigna radiata L.), zinc (Zn), manganese (Mn), leaf epidermis, stomata

Key findings: Zinc and manganese levels and their interactions in mung bean cultivars significantly influenced all the growth parameters. The mung bean genotype Black Indian outperformed most cultivars for most traits.