Evaluation of characteristics contributing to hay yield and adaptability of Aksu white sweet clover

Characteristics contributing to hay yield and adaptability of Aksu white sweet clover (Melilotus albus) were analysed and compared among four Melilotus cultivars and four wild Melilotus germplasm resources. The experiment was conducted at the campus experimental station of the Animal Science College, Tarim University, located in Alar, Xinjiang (40°54'21'' N, 81°30'20″ E). The results showed that the squaring and initial bloom stage of Aksu white sweet clover was on the 64th and 75th day after emergence, respectively. The number of growth and development days was very short and its hay yield was 5 874.23 kg·hm-2, which was 18.76%~67.20% greater than that of the control group. Plant height and the fresh-dry ratio were 125.27 cm and 4.23, respectively, which were greater than those of the control group, indicating better hay yield characteristics. Its water-holding and summer survival rate was 65.00% and 99.00%, respectively, indicating good adaptability to the megathermal and arid climate of the Aksu area. The comprehensive performance score ranked first among the tested accessions, which demonstrated it had potential to be transformed into wild varieties.