Effects of humic acid on vegetative characteristics of Festuca arundinacea

To investigate the effects of humic acid on vegetative characteristics of a rangeland species, Festuca arundinacea, a greenhouse experiment was conducted at Damavand city, Iran, based on a randomized complete block design. Levels of 0, 75, 150, and 225 kg per hectare of humic acid were used in a form of granules as different treatment levels. Several vegetative characteristics were studied and recorded on the single plants. Analysis of variance showed that treatment effects on leaf area, leaf number, leaf, stems and whole canopy fresh weight, leaves, stems and roots dry weight, root length, canopy to root ratio, total chlorophyll and chlorophyll a were significant at 5% level. Also, the treatment effects on canopy dry weight and root fresh weight were significant at 1% level. Treatment effect was not statistically significant on tiller number, collar diameter and chlorophyll b. Maximum dry and fresh root weight were obtained by 75 kg per hectare humic acid. Most of the attributes were highly affected by applying 225 kg per hectare humic acid.