Effect of zinc on some physiological growth characteristics of different cultivars of maize (Zea Mayes L.)

Abstract: A field experiment was conducted during the summer season 2019 at Al-Qurna Agricultural Research Station (80 km north of Basra Governorate). The aim of this study to find out the response of five cultivars of corn (Fajar-1, Baghdad, Maha, Sarah, and 5018) to spraying zinc with three concentration (0, 25 and 50 mg L-1) and the interaction between them. The experiment was carried out using a randomized complete block design using split plots with three replications. The results indicated that Zn2 level achieved the highest values for all studied traits, with a grain yield of 5.217 tons per hectare. The 5018 cultivar recorded the highest values for leaf area (LA), crop growth rate (CGR), plant height, stem diameter, and grain yield (4.210 tons.ha-1). Meanwhile, the Maha cultivar excelled in net assimilation rate (NAR), with no significant difference from the Sarah cultivar. In most traits, cultivar 5018 excelled at the Zn2 level in most studied growth traits, recording the highest values for leaf area (LA), crop growth rate (CGR), plant height, and stem diameter. Meanwhile, cultivar Maha at the same level recorded the highest values for net assimilation rate (NAR) and grain yield (5.773 tons.ha-1), with no significant difference from cultivar 5018 at the same level, which recorded 5.713 tons.ha-1. Key findings: Zea mays varieties responded positively to different levels of zinc, enhancing growth traits and yield. The Zn2 level was the most effective among the levels under study, and there was a significant interaction between variety 5018 and Zn2.