Effects of Combined Application of Nitrogen (N) and Iron (Fe) on Chlorophyll Index and Some Growth Characteristic of Corn Plant under Greenhouse Conditions

In this research, the effects of combined application of nitrogen (N) and iron (Fe) on the chlorophyll index and some growth characteristics of corn were studied using a factorial experiment based on completely randomized design with three replications under greenhouse conditions. The factors were N from two sources including urea and sulfur coated urea (SCU) in 3 levels (0, 100 and 200 mg N kg-1) and the Fe from two sources including commercial Fe-EDDHA and ferrous sulfate (FeSO4.7H2O) in 3 levels (0, 10 and 20 mg Fe kg-1). The results showed that the main effects of both sources of N and Fe on chlorophyll index and growth characteristic of corn plan were significant (p<0.01). Also, the interaction effect of N and Fe on shoot dry weight and leaf chlorophyll index was significant (p<0.05), so that the maximum shoot dry weight of corn was obtained with 200 mg N kg-1 as urea with 10 mg Fe kg-1 as Fe-EDDHA. The maximum leaf chlorophyll index was recorded in treatment with 200 mg N kg-1 from source of SCU with 20 mg Fe kg-1 as FeSO4.7H2O. In the most studied traits the difference between the two nitrogen sources, namely, urea and SCU was not significant.