Association of agronomic and forage quality traits in red clover (Trifolium pratense L.)

Red clover (Trifolium pretense L.) is a source of highly nutritional voluminous forage for livestock feed. The objectives of this investigation were to: I) annotate associations of agronomic and forage quality traits of red clover accessions; II) group accessions in relation to analyzed traits. The plant material used included 46 cultivars and local populations, which originated from 17 countries, representing part of the red clover collection from the Institute of Field and Vegetable Crops in Novi Sad, Serbia. The field trial was sown during two growing seasons in Novi Sad. The agronomic traits (plant height-PH, internodes number per stem-IN, green mass yield-GMY, dry matter yield-DMY) were evaluated from the second cut in the nursery of the second year of life. Forage quality traits analyzed were content of neutral detergent fibers (NDF), acid detergent fiber (ADF), and crude protein (CP). In regard to very strong associations of PH, GMY and DMY, and to moderately strong associations of PH and IN, it could be anticipated that the indirect selection for higher plants with higher IN can lead to higher GMY and DMY. The breeding of red clover for NDF and ADF and elevated CP might be successful, but can reduce herbage yield (due to very weak positive and negative associations with GMY and DMY). The accessions were grouped to the six clusters which can facilitate selection and breeding for different agronomic and quality objectives.