Evaluation of silage performance and nutritional quality of different corn cultivars in Qinghai Plateau

In order to screen for the silage corn cultivars suitable for cultivation in the Qinghai Plateau area, the silage performance and nutritional quality of 50 corn cultivars were evaluated using principal component analysis and cluster analysis. The results showed that 1) the main agronomic characteristics of the tested cultivars were significantly different (P < 0.05). The variation range of plant height and ear height was 270.30～378.90 cm and 84.40～195.60 cm, respectively. The variation range of fresh weight and dry weight was 0.70～2.70 kg and 0.30～1.03 kg, respectively. The average number of leaves ranged from 10 to 19 per plant, and the variation range of leaf greenness was 53.18% to 97.67%. The protein content (dry matter basis) of the tested cultivars was 6.16%～13.81%, and the levels of neutral detergent fiber and acid detergent fiber (dry matter basis) were 29.75%～61.13% and 16.45%～33.45%, respectively. 2) With reference to the quality grading standard of silage corn, 50 tested cultivars could be graded simply, of which 19 were classified as first-level, 12 as second-level, and 8 as third-level. 3) The cumulative contribution of the top five principal factors was 84.644% in the principal factors analysis. There were 24 corn cultivars that performed well in comprehensive traits and were suitable for planting in this area. 4) Cluster analysis grouped the tested cultivars into four categories that can be selected and utilized according to the breeding objectives. Comprehensive analysis results showed that the Gaokeyu 138 variety was suitable for planting as silage corn in Qinghai.