Studies on nutritive yield of green mowed Jerusalem artichoke : Part 1 Seasonable changes of nutrient components in leaves and stems

(1) As a fundamental study for cultivation and utilization of green mowed Jerusalem artichoke, seasonable changes were investigated of nutrient components in leaves and stems. (2) As regards to the height of plant and weight of dry matter of leaves and stems, the biggest increase in average per day was observed in August. Remarkable decrease, however, was seen in leaf-stem ratio during this period. (3) Crude protein was found more in leaves than in stems. Crude protein which was abundant both in leaves and stems at the early stage of growth, rapidly decreased after August. Much protein N was found in leaves, whilst non-protein N found in stems. (4) More total sugar was found in stems than in leaves. Almost equal quantities of reducing sugar were found in both leaves and stems. At the early stage of growth, large quantities of total sugar and reducing sugar were found in stems. In summer, these quantities decreased, but again increased in autumn. In Case of leaves, these quantities were small at the early stage of growth, but gradually increased afterwards. Ratio of reducing sugar against total sugar was higher in leaves than in stems. (5) More nitrogen free extract and carbohydrate were found in stems than in leaves. Both in leaves and stems, these two components increased with the growth of plant, but in autumn decrease was observed in stems. Ratio of carbohydrate against nitrogen free extract was higher in stems than in leaves. Carbohydrate in stems could more easily be changed into sugar than that in leaves. (6) As a result of applying additional fertilizer, nitrogen free extract decreased temporarily, whilst crude protein increased on the contrary.