Intra-species variations in yield and quality determinants in Vicia species: 1. Bitter vetch (Vicia ervilia L.)

Variations in days to flowering and pod maturity, harvest index, as well as yields of hay, grain, and straw among 25 bitter vetch (Vicia ervilia L.) accessions were examined over four cropping seasons in a non-tropical dryland environment in north-west Syria. Crops were harvested at flowering to determine hay yield, and at maturity to determine grain and straw yields. Concentrations of hay and straw crude protein (CP), acid detergent fibre (ADFom), neutral detergent fibre (aNDFom), in vitro organic matter (OM) digestibility, and grain CP were analyzed. Days to flowering and pod maturity, harvest index (0.26–0.35), as well as yields (kg DM/ha) of hay, (2738–3435), straw (3408–4033), and grain (1285–1959) varied (P<0.05) among accessions. Concentrations (g/kg DM) of hay CP (146–178), ADFom (200–230), aNDFom (335–395), and IVOMD (742–777 g/kg OM); straw CP (82–120), ADFom (282–321), aNDFom (464–508) and IVOMD (483–591 g/kg OM); and grain CP (273–285) also varied (P<0.05) among accessions. Grain yield was correlated with days to flowering (r = −0.83, P<0.001; YGrain yield = 5976.38–45.75Day to flowering, r2 = 0.69), and harvest index (r = 0.90, P<0.001; YGrain yield = 69.41Harvest index − 495.78, r2 = 0.81). Straw CP was correlated with ADFom (r = −0.78, P<0.01; YStraw ADFom = 374.42 − 0.738Straw CP, r2 = 0.59,) and IVOMD (r = 0.87, P<0.001; YStraw IVOMD = 269.47 + 2.78Straw CP, r2 = 0.76), while straw IVOMD was correlated with ADFom (r = −0.79, P<0.01; YStraw IVOMD = 1333.64 − 2.64Straw ADFom, r2 = 0.53). Results provide quantitative data on intra-species variations in phenology, as well as yields and quality determinants of hay, grain, and straw in bitter vetch, and demonstrated that yields and quality of hay, grain and straw can be used to identify promising bitter vetch accessions. Accessions 508, 2510, 2511, 2514, 2515, 2517, 2519, 2520 and 2522, have better potential for hay and grain production in non-tropical dry areas.