EFFECT OF LEVELS AND METHODS OF ZINC ADDITION ON THE GROWTH AND YIELD OF WHEAT CULTIVATED IN SALINE SOILS

A field experiment on loamy soil was conducted in the Haditha district, Anbar province, Iraq, during the winter season of 2021-2022. The study aimed to determine the effect of different zinc levels and methods on wheat growth, yield, and tolerance to salinity. The experiment used a randomized complete block design (RCBD) with a split-plot arrangement and three replications. The seeds were soaked before planting with three zinc levels: 0 (control treatment, soaked in water only), 75 mg Zn Kg-1 (seeds soaked in zinc at a concentration of 75 mg Zn Kg-1), and 150 mg Zn Kg-1 (seeds soaked in zinc at a concentration of 150 mg Zn Kg-1) for eight hours. This was followed by two spray applications of the same concentrations, the first at the tillering stage and the second at the booting stage. Statistical analysis showed that adding zinc to soak the seeds and spraying it on the plants increased plant height, number of tillers, flag leaf area, grain yield, and 1000-grain weight. Additionally, it was observed that seed soaking and plant spraying with zinc increased the plant's tolerance to salinity by reducing the chloride and sodium concentration in the wheat straw and roots and increasing the potassium concentration and the potassium/sodium ratio in the wheat straw and roots. The best results were obtained using the 150 mg Zn Kg-1 level (seed soaking and plant spraying) for most of the studied characteristics.