Effects of humic acid foliar spraying and nitrogen fertilizer management on yield of peanut (Arachis hypogaea L.) in Iran

In order to study effects of humic acid foliar spraying and nitrogen fertilizer management on yield and yield components of peanut (Arachis hypogaea L.). An experiment in factorial format based on randomized complete block design with three replications, during 2011 year in Astaneh Ashrafiyeh (north of Iran) was conducted. Factors of experiment includes two levels of foliar humic acid spraying (H1: 0 (control) and H2: 40 mg/l) and four levels of nitrogen fertilizer levels consist of (n1: 0 (control), n2: 25 kg/ha, n3: 50 kg/ha, n4: 75 kg/ha pure nitrogen from source of urea). In maturity time, seed yield, straw yield, biological yield and harvest index were measured. Effects of humic acid foliar spraying and nitrogen management on all traits were significant at 1% probability level. Interaction effect of humic acid and nitrogen management on seed yield, straw yield and harvest index showed significant differences at 5% probability level. Also, on biological yield was non significant. With attention to results of experiment, with increase nitrogen application up to 75 kg/ha all studied traits were increased. In all measured traits, the treatment of 40 mg/l humic acid foliar spraying was superior.