Variability and Correlation of Yield and Forage Quality in Alfalfa Varieties of Different Origin

Alfalfa is the most important forage plant species. There are numerous alfalfa varieties in the world with improved yield potential and forage quality. Many of them have also been created in the region of Southeast Europe, using various breeding techniques. This investigation was carried out in central Serbia and it included 15 alfalfa varieties of different origin (nine from USA and six from Europe). The objective was to determine their yield in each cut and total dry matter yield (TDMY) in the second (A1) and third (A2) year of exploitation, as well as forage quality: the content of mineral matter (MM), crude protein (CP), crude fiber (CF), crude fat matter (CFM) and nitrogen-free extract (NFE). Investigated varieties exhibited high total variability in dry matter yield (DMY) (A1: CV= 13.19%; A2: CV= 9.33%). DMY variability was higher with the varieties from USA (A1: CV= 13.65%; A2: CV= 9.92%) than with those from Europe (A1: CV= 6.67%; A2: CV= 8.01%). Varieties from USA also proved more variable in crude protein (CP) content than European varieties (CV= 6.27% and CV= 2.68%, respectively). Differences between the investigated varieties (genotypes) also influenced total variability of forage quality parameters, with total CV ranging from 5.07% for CP to 10.48% for CF. Dry matter yield (DMY) had significant positive correlation with CP (r= 0.344), CF (r= 0.342) and CFM (r= 0.306), and the strongest correlation, although negative, was between CF and NFE (r= -0.917).