Abstract
It was studied to evaluate the influence of infection of spring black stem fungus Phoma medicaginis Malbranche et Roumeguere on the feed composition and nutritive value of alfalfa (Medicago sativa L.). The investigation was carried out on the samples from variety-test-fields of the National Institute of Animal Industry, Chiba in 1970 and the Aichi-ken Agricultural Research Center, Aichi, Japan in 1975. The disease severity of alfalfa spring black stem was higher in southern habitat origin varieties (I-Group) than in northern origins (IV or V-Group). This result was correspondingly with the data of FUKUSHIRO and FURUTA (1985). The health and diseased samples were collected from each variety for determination of feed composition and evaluation of nutritive value. In alfalfa varieties, Sonora and Du Puits, which shown high disease severity, contents of crude protein, soluble carbohydrate, crude fat, dry matter digestibility, total digestible nutrient and digestible crude protein were lower in the diseased sample than healthy. The change of nutritive quality in alfalfa variety Rhizoma which indicated low disease severity of spring black stem was not clear. The results were the same as on the two experimental field or in different year. These results indicate that the severe spring black stem infection cause considerable qualitative damages on the alfalfa.
