تاثیر فسفر و روی بر رشد و ترکیب شیمیایی ذرت

Micronutrients availability including that of Zn is critical for optimum growth of plants. Zinc availability in calcareous soils of Iran is relatively low due to the presence of a large amount of CaCO3 and high pH levels. Overapplication of phosphorus to soils may also cause P-induced Zn deficiency. The objective of this experiment was to evaluate the effect of phosphorus and zinc application on the growth and chemical composition of corn (Zea mays L.) under greenhouse conditions. Treatments consisted of a factorial combination of 5 levels of P (0, 25, 50, 100 and 200 µg P/g soil as KH2PO4) and 3 levels of Zn (0, 5 and 10 µg Zn/g soil as ZnSO4. 7H2O) in a completely randomized design with 3 replications. Plants were allowed to grow for 60 days and then cut at the soil surface. Results showed that P and Zn applications increased top dry weight. Applied P increased P concentration and total uptake in plants, but decreased Zn concentration and had no effect on Zn uptake. Zinc application decreased P concentration of com but increased Zn uptake and concentration. The P: Zn ratio in plants increased with P application but decreased with Zn addition. Application of P and Zn increased Fe concentration in plant but decreased Mn concentration and had no effect on Cu concentration. Prior to making any fertilizer recommendations, more research is required to precisely evaluate the response of com to P and Zn applications under field conditions.