Effect of phenological stages on dry matter and quality components in lucerne.

摘要

In field trials in 1989-93 at Foggia and in 1990-93 at Lodi, Italy, 8 Medicago sativa cultivars were cut early or at the normal cutting date (40% of tillers at the green bud and flowering stages, respectively). Early cutting reduced dry matter yieldat both sites (11.3% at Foggia and 23.6% at Lodi) and ground cover index at Lodi, and increased leaf:stem ratios (24.6%) at Foggia. Differences in agronomic adaptation were found among cultivars. Crude protein contents at the normal cutting date were lower (5.0% in leaves and 8.7% in stems) than with early cutting. Percentages of neutral detergent fibre (NDF), acid detergent fibre (ADF) and lignin (ADL) in leaves were influenced by cutting date. As a consequence of the large interaction (year X cuttingdate X cut X cultivar), no statistically significant variations were found among cultivars in qualitative parameters of the herbage. Treatment effects on herbage quality were more evident in leaves than in stems and their contents of ADF, ADL and NDF were related to the phenological stage.