Differences in the Zinc Efficiency Among and Within Maize Cultivars in a Calcareous Soil

Low availability o f Zn in cal careous soils is o ne of the w idest ranging abiotic stresses in world agriculture. Greenhouse experiment were carried out with Four cultivars of maize (301 Single Grass (A), 302 Single Grass (B), 307 Single Grass (C), 400 Single Grass (D), Zea mays L.) were used to study the influence of varied zinc (Zn) supply on Zn efficiency, shoot dry matter production, Zn uptake, Chlorophyll content, Leaf Area Index (LAI) and Relative Growth Rate (RGR). Plants were grown in a Zn-deficient calcareous soil under greenhouse conditions with (+Zn = 10 mg/ kg soil) and without (-Zn) Zn supply. Plants were harvested after 40 and 80 days. Zinc efficiency, expressed as the percentage of shoot dry weight produced under conditions of Zn deficiency compared to Zn supply, ranged between 62.3 and 75.5% in first stage and between 63.5 and 81.2% in second stage. Application of Zinc caused increase in shoot dry weight in all cultivars. Zn uptake enhanced with application of zinc and ranged from 100.80 to 231.91 μg/pot in first stage and 458.01 to 858.83 μg/pot among cultivars. Zinc application incre ased the Chlorophyll content, Leaf Area Index and Relative Growth Rate. Zn efficiency had high and positive relation with Shoot dry weight and Zn uptake in different cultivars.