Effects of the Developmental Stage at Harvest on Dry Matter and Chemical Component Partitioning in Berseem

The influence of cutting applied at four stages of plant growth on dry matter, crude protein, total available carbohydrates and reducing sugar partitioning was examined in six genotypes of berseem (Trifolium alexandrinum L.). The research was conducted in Foggia (Italy) during 1990 and 1991 in a glasshouse with controlled water application. The plants were grown in a plastic‐lined, PVC cylinder. At each cut, dry matter and chemical components were evaluated in leaf, stem and root fractions; at the end of the biological cycle, seed yield was recorded. Plants showed similar dry matter partitioning between leaves and stems at the eighth internode stage. The crude protein concentration was highest in leaf fractions, reaching the maximum value (31%) at an early stage of growth (fourth internode stage). The maximum value of total available carbohydrates was obtained in the stems at the early flowering stage (11 %), whereas reducing sugars almost always showed higher concentrations in the leaves (4 %). As for forage and seed yields, the developmental stage at cutting had a great influence on dry matter and chemical component partitioning among the different organs. Genotypic differences were observed for dry matter partitioning in leaves and stems in all developmental stages, but diversity in chemical component content was more evident in the roots.