Effect of humic acid application on agronomic characteristics of some varieties of clover (Trifolium sp.)

In order to evaluate the effect of humic acid application on agronomic characteristics of some varieties of clover (Trifolium sp.), a field experiment was conducted as factorial based on randomized complete block design with three replicates at Research Field of Faculty of Agriculture, Shahr-e-Kord University, Shahr-e-Kord, Iran in 2013. Three varieties of clover (Bersim, Haftchin (Persian) and Kermanshahi) were considered as the first factor and three levels of humic acid applications [control (without humic acid), 5 and 10 lha-1] as the second factors. Results showed that shoot dry weight, dry weight per plant, root and shoot dry weight per plant, plant height, number of leaves and stem diameter were affected by interaction effect of variety×humic acid. First and Second time of harvest had 57% and 43% of the most values of treatments, respectively. Haftchin and Kermanshahi varieties had the highest and Bersim had the lowest values of the treatments. Humic acid with 10 l ha-1 produced the highest values of measured treatments. In general, application of 10 liter humic acid per ha produced the highest values of shoot dry weight by 3410 and 3800 kg ha-1 in Kermanshahi and Haftchin varieties, respectively. Bersim produced the lowest value of shoot dry weight by 686 kg ha-1.