Corn Silage (Zea mays L.) Response to Zinc Foliar Spray Concentration When Grown on Sandy Soil

The objective of this study is to identify an adequate zinc (Zn) foliar spray concentration which corrects Zn deficiency without disrupting other plant mineral contents, enhances plant growth, and thereby corn silage yield when grown on sandy soil. A field experiment was conducted using five Zn foliar spray concentrations (w/v): 0.03%, 0.07%, 0.10%, 0.14% and 0.18%. Zn sulfate (ZnSO4. 7H2O) was used as a source of Zn. Zn foliar application was realized at two growth stages (6-7 and 9-10 leaf stages). A treatment without Zn foliar spray was maintained as control. The results showed a quadratic response of corn silage towards Zn foliar spray concentrations, in which 0.09% was the optimum value for overcoming Zn deficiency. Such level increased shoot Zn concentration at harvest from 15 mg kg to 21.8 mg kg, didn’t decrease plant mineral content below critical levels, enhanced plant growth and raised silage yield by 49.4% compared to control. On the other hand, Zn foliar spray concentration up to 0.10% induced visible leaf damage, growth inhibition and a decrease of 26% in silage yield compared to Zn foliar applications at 0.09%.