Abstract A greenhouse experiment was conducted using a zinc-deficient soil treated with 0, 1.25, 2.5, 5, 10,20 and 40 ppm Zn to study the effect of Zn application on growth and Zn content in various plant parts at three stages of maize growth. Plants showing severe deficiency symptoms were stunted and had a relatively high Zn concentration. The lowest rate of Zn application prevented the development of Zn deficiency symptoms even after ten weeks' growth. Dry weight of whole shoots was greatest at 5.0 ppm Zn at all sampling dates. Concentration of Zn decreased with both age of leaf blade and age of plant. The leaf blade 3 from the top is the most sensitive in relating relative yield of shoots to Zn concentration in the tissue. For plants harvested after 6, 8 and 10 weeks the critical Zn value for leaf blade 3 lies between 12.0 and 14.2 ppm for optimum dry weights of maize shoots.