Effects of different irrigation levels on some quality and quantity traits of grass pea (Lathyrus sativus L.)

at the research farm of Vali-e-Asr University of Rafsanjan in 2013. The experiment was arranged in a randomized complete block design with four replications and four irrigation intervals. Irrigation was done after 40 (control), 60, 80 and 100 mm evaporation from pan class A, from seedling establishment till physiological maturity. Results showed that irrigation level did not significantly change percentage of qualitative traits including Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Acid Detergent Lignin (ADL), starch and crude protein as well as 1000- seed weight. However, above mentioned qualitative traits content as well as seed number per plant, seed and biological yield were significantly affected by irrigation interval. Based on mean comparison results, only 100 mm evaporation treatment significantly reduced qualitative traits content and there were no significant differences between 40 to 80 mm evaporation. Also, seed yield, seed number per plant and shoot biomass were the highest in 40 mm (165.5 g/m2, 36.17 per plant and 2.4 g/plant, respectively) and the lowest in 100 mm irrigation treatment (63.1 g/m2, 24.5 per plant and 1.07 g/plant, respectively). Based on the results, it seems that grass pea qualitative forage yield is relatively tolerant to water deficit till 80 mm evaporation.