Effect of plant density on qualitative and quantitative indices of different species of vetch (Vicia spp.)

Effects of three plant densities (100، 150 and 200 seed per m2) on qualitative and quantitative indices of three species of vetch including broad leaf vetch (V. narbonensis L.)، common vetch (V. sativa L.) and woolly pod vetch (V. dasycarpa L.) were evaluated under fall seeding (dryfarming) conditions during 2007-2008 crop years. the experiment was conducted at the Agricultural College of the University of Lorestan in a factorial arrangement of based on randomized complete block design (RCBD) with three replications. The highest hay yield was obtained on broad leaf vetch with density of 200 plant per m2 (2268 kg/ha) and the lowest hay yield (724 kg/ha) was recorded on woolly pod vetch with density of 100 plant per m2. Average hay yield was recorded on broad leaf vetch and common vetch with density of 100 plant/m2 equal to 1856 and 1714 kg/ha، respectively. The highest portion of leaf and stem dry weight (54. 18 and 45. 82%) was observed on broad leaf vetch with 150 plant/m2، respectively. Also، ratios of leaf and stem dry weight in woolly pod vetch were 34. 6% and 68. 05%، respectively which were superior two other species. The results showed that qualitative indices such as crude protein (CP) percentage and neutral detergent fibers (NDF) were affected by plant density and species. Thus، the highest CP and NDF values (23. 14 and 29. 95% respectively) were obtained from woolly pod vetch species in 200 plant/m2 and the lowest values of the characters (19. 78 and 25% respectively) were recorded on broad leaf vetch with 100 plant/m2،.