Sainfoin (Onobrychis viciifolia Scop.), as a tetraploid (2n = 4x = 28) perennial forage legume, which belongs to the Fabaceae family, is rich in proteins and some secondary plant metabolites. A field experiment including 32 common sainfoin genotypes was set up with the aim of determining some morphological traits. The following traits were measured: number of stems per plant (NSP), number of nodes per main stem (NMS), height of longest stem (HLS), peduncle length (PL), length of inflorescence (LI), number of internodes per main stem (IMS), internode length (IL), number of leaves per main stem (LMS), number of leaves per stem (LS), and number of leaflets per leaf (NLL), dry weight total (DWT), number of plants per area (NPA) and stem weight / leaf weight ratio (SLR) traits. Positive and statistically significant correlations were determined between DWT and all of the measured traits except for IL. The length of inflorescence was significantly positively correlated with number of leaves per stem (LS) and number of leaflets per leaf (NLL), IL and LMS. Also, we found significant positive correlation between IL and LMS, as well as between LMS with LS and NLL. The positive significant correlations were observed between LS with SLR and NLL as well as between SLR and NLL. The importance of main stem properties like length or height, number of leaves, and number of leaflets can be seen for selection, in genetic improvement programs.
