The effects of iron application to soil and foliarly on agronomic properties and yield of peanut (Arachis hypogaea)

The effects of iron application on some agronomic properties and yield of peanut were determined by measuring basic agronomic properties such as micronutrient contents of soil, leaf and grain samples, oil and protein contents of grain and hundred seed weight. Variety-dose trial was established in 2006 and 2007. Soils were treated with providing 0, 10, 20 and 40 kg ha(-1) iron whereas foliar applications were undertaken with 0, 1, 2 and 3 kg ha(-1) iron following twenty days of flowering. Iron contents of soil samples were higher than threshold value of 4.5 mg kg(-1) which ranged from 7.52 to 9.34 mg kg(-1). However, even at this adequate soil Fe, phenological observations revealed iron chlorosis. The average yield in soil treatment at zero dose plot Fe of NC-7 variety was 4417.2 kg ha(-1) and increased up to 4848.6 kg ha(-1) with application of Fe 10 kg ha(-1). Similar results were found for COM variety in soil Fe treatments. The yield of COM variety for zero dose was 4553.3 kg ha(-1) and increased to 5273.0 kg ha(-1) with Fe 10 kg ha(-1) applied plot. The maximum amount with 5317.6 kg ha(-1) yield was achieved at 20 kg ha(-1). The applications of Fe significantly increased (P<0.01) peanut yield and hundred seed weight. The highest yield of 6030 kg ha(-1) in 2007 was obtained with 2 kg ha(-1) foliar to COM variety, the lowest yield of 3890 kg ha(-1) in 2006, was determined at NC-7 variety which was control. Fe applications had similar positive effects on 100 grain weight. However, oil yield and protein contents of peanuts did not respond to treatments. Economic analysis revealed that the highest income of 10208.0 $ ha(-1) was obtained with foliar application of 1 kg ha(-1) Fe.