Since productivity and root growth of Indian corn is thought to be different by cultivation conditions, the following experiments were carried out from May to August, 1968, to clarify the influence of plant density and ridging height. 1. Influence of plant density : Weights of leaves and stalks (top) were heavier in the high density plot than in low one, while root wieghts of both plots were the same. 2. Influence of ridging height : Top weights were heavier in order to the heights of ridge. Contrary to this root weight was heaviest in unridged plot, and there was no difference between the root weight of 10cm ridging height plot and that of 15cm ones. The root amount increased in unridged plot is due to promoted growth of prop aerial roots and fibrous root. 3. The higher productivity in high density plot may be due to more efficient utilization of solar energy by greater LAI, and less productivity of unridged plot may be due to higher distribtion of assimilates to root. 4. Chemical composition in plant : Crude protein percentage decreased in the whole plant, but NFE in top and crude ash in root increased, with the stages of growth. In unridged plot a tendency towards less nitrogen and more rapid accumulation of carbohidrate (total sugar etc.) than in ridged plot was recognized.

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An experiment was conducted to make it clear that the variations in silage quality caused by various levels of initial air inclusion in ensiling were due to whether the direct effect of the included air itself or the indirect effect of it that related to the degree of seepage of plant juice resulted from the degree of compaction at ensiling. Two high moisture Italian ryegrasses of different water soluble corbohydrate contents and the wilted one were used in this experiment. The following four experimental groups were designed with each material. Control group ; chopped materials were ensiled in small laboratory silos at three levels of initial air inclusion of low (L) (41.6%), middle (M) (56.2%) or high (H) (70.8%) and completely air-tightened. Minced group ; chopped materials were further minced in order to equal the degree of secretion of plant juice and ensiled in the same way as the control group. Nitrogen-replaced (N-replaced) group ; chopped materials were ensiled in the same way as the control group and the inc luded air in each silo was replaced with nitrogen after exclusion of air. Minced and N-re placed group ; minced materials were ensiled in the same way as the control group and the air was replaced with nitrogen. All silages were stored at about 15℃ for 35 days. Lactic acid contents based on those at the (L) of initial air inclusion of each group were, on average of three materials, (L) : (M) : (H)=100 : 94 : 79 in the control, 100 : 99 : 88 in the minced, 100 : 95 : 90 in the N-replaced and 100 : 98 : 93 in the minced and N-replaced, respectively. This result showed that differences in lactic acid contents in the control group were reduced by using each of mincing or N-replacing and more reduced by using them together. Variations in lactic acid contents resulted from the treatments were expressed as per cents on those of the control group. They were, on average of three materials, control : minced : N-replaced : minced and N-replaced=100 : 101 : 95 : 99 at the (L) of initial air inclusion, 100 : 107 : 96 : 104 at the (M) of it and 100 : 112 : 109 : 118 at the (H) of it respectively. This result showed that lactic acid contents increased at every levels of initial air inclusion by mincing but they decreased at both the (L) and (M) of initial air inclusion and increased only at the (H) of it by N-replacing. From these results it was suggested that the influence of level of initial air inclusion on quality of silage was in relation to both the direct and indirect effects of the included air, and in the former it acted as to inhibit the production of lactic acid at both high and low levels of initial air inclusion, in the latter to stimulate more lactic acid production at the lower level of initial air inclusion, and the influence of level of initial air inclusion on quality of silage was the result of interaction between these inconsistent actions.

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In this paper it was studied whether the influence of level of initial air inclusion on quality of silage was unchangeable irrespective of various conditions at ensiling or changeable under certain circumstances. It was also studied that from what the direct effect of the included air itself was resulted. The longer chopped high moisture Italian ryegrass of low water soluble carbohydrate (WSC) contents, the shorter chopped one of the same grass and the shorter chopped one of high WSC content were used in this experiment. Each material was ensiled at three levels of initial air inclusion of low (L) (42.1%), middle (M) (56.6%) or high (H) (71.0%) and completly air-tightened. Ten silages of the same level of initial air inclusion were made with each material. All silages were stored at about 25℃ and they were opened at intervals of 6, 12, 24 hours, 2, 3, 5, 7, 14, 21 and 35 days after ensiling. With the longer chopped low WSC material and the shorter chopped high WSC one, the quality of silage was highest at the (L) of initial air inclusion and it was lowered at the (M) and (H) throughout the experimental period. With the shorter chopped low WSC material however, the quality of silage was highest at the (L) for five days after ensiling but it was highest at the (M) after seventh day of ensiling. This result showed that the influence of level of initial air inclusion on quality of silage was changeable according to the degree of seepage of plant juice and the level of WSC content. The relation between the degree of respiration of the included air at ensiling and the quantity of WSC consumed and the degree of temperature rise at that time was studied. With the material of low WSC content, the ratios of WSC consumed to total WSC were (L) : (M) : (H)=1.5% : 2.8% : 5.2% and degree of temperature rise were 0.7℃ : 1.3℃ : 2.4℃ respectively. This result showed that the lactic acid would be more produced and the quality of silage would be higher at the lower level of initial air inclusion. This was contradictory to the fact that the included air itself acted as to inhibit the lactic acid production both at the (L) and (H) of initial air inclusion. From these results it was suggested that the degree of respiration of the included air at ensiling was not directly in relation to the effect of the air itself and main effect of it was probably to act directly on the microflora and to change their population or activities according to their differences in tolerance to air.

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Variation of carbohydrate contents in the top of orchardgrass with the descending of temperature during autumn was investigated. Carbohydrates extractable with 85% ethanol were much sucrose, fructose and glucose in descending order, and the total amounts of sugars were not so variable, about 4 to 5% in leaf sheath and 5 to 10% in leaf bladas, as fructosan during the three months of the test period. In the ethanol extractable fraction, the shorter chain of fructosan was also contained 3 to 5% within the total fructosan early and 1 to 2% late in the that period. Fructosan in the leaf sheath was about 10% of the air dry matter early in October, but increased afterwards and attained to 50% over early in December. Fructosan in leaf blade also increased with descending temperature as well as in the leaf sheath, but its amount was not so much only 20% even in early December. Variation in molecular weight of fructosan in leaf sheath during Autumn was also investigated by methods of gel filtration and of fractionation with various concentrations of ethanol. Fructosan from leaf sheath sampled early in October was efluented in the wide range of volume between Dextran 10 (Mw-1, 1200, Mn-5, 700) and Dextran 20 (Mw-22, 300, Mn-15, 000) by means of Sephadex G-75 gel column chromatography. Fructosan from leaf sheath sampled early in December, on the other hand, was efluented in the volume corresponding with dextran 20 or larger. The alcohol extractable amount of fructosan from dry meal sample of leaf sheath increased linearly with decreasing ethanol concentration in X/9th sample, but increased abruptly at low concentrations of ethanol in XII/9th sample. It may be concluded that fructosan in the leaf sheeth increases not only in its amounts, but also in degree of polymerization with the doscending of temperature in Autumn.

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Difference in the composition of the nonstructural carbohydrates in leaf sheath among several perennial grasses was investigated. In the soluble fraction with 85% ethanol, a part of fructosan was distributed together with sugar such as glucose, fructose and sucrose. Amount of fructosan extractable with 85% ethanol was more in the leaf sheath containing fructosan of lower molecular size, for example as much as 20% of total fructosan in tall fescue, in which DP. of the predominant fructosan appeared to be smallest of the tested samples. Molecular sizes of fructosan determined with Sephadex gel filtration, being highest in timothy and descending in order of orchardgrass, perennial ryegrass, meadow fescue, redtop and tall fescue. The same results were obtained by determining the ratios of glucose component in their fructosan molecule. Degrees of polimerization of fructosans from redtop and tall fescue were approximately 10, perennial ryegrass and meadow fescue 20 to 30 and orchardgrass approximately 50. The predominant fructosan from timothy showed remarkably high DP. as compared with others.

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Such agronomic traits as forage yield, plant height, tiller weight and tiller number-were measused on twenty early and late varieties of Italian ryegrass at each clipping time. Clippings were carried out by two different methods, one clipped twice a year at each heading time (1st and aftermath) according to their maturity, the other clipped three times from April to June. On frequent clipping plots, typical varietal patterns appeared on the trend of forage yield due to the differences of such ecological characteristics as early spring growth, earliness of booting stages and amount of regrowth. It was considered that forage yield of the last clipping of both methods depended mainly on the ability for regrowth. No close relation was detected between forage yield clipped at heading time and that clipped frequently. The result suggests that evaluation on each variety differs with methods of clipping and that selection for yield should be done in consideration of this fact. As for correlation between yield and its component characters, the trait that was the most closely correlated with forage yield was plant height and the next was tiller weight. Tiller number was, in most cases, not highly correlated with forage yield.

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Tryptophan (Try) metabolism of Rhizobium meliloti was examined. The relative ratio of the components of decomposition products varied with culture age. Anthranilic acid was identified as an oxidation product. Exogenous anthranilic acid and indole-3-acetic acid (IAA) were not oxidized by this bacterium cultured in the Try medium. This is an indication that anthranilic acid was an end product and was not formed via IAA.

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1) This experiment was conducted in order to clarify the effect of temperature on the regrowth of herbage plants. Some cool season grasses and warm season grasses were used for this experiment. 2) There was close relation between the regrowth and the temperature after defoliation. Within a range of 15-30℃, the higher the temperature, the more was the regrowth of warm season grasses, Dallisgrass and Rhodesgrass. 3) But in the case of regrowth of cool season grasses Italian ryegrass and Perennial ryegrass, there was little difference within a range of 15-30℃ temperature. 4) A tendency that the higher the temperature before defoliation, the less was the regrowth of herbage plants was recognized. 5) It was considered that the difference of temperature before defoliation affect the TAC content and the regrowth-tiller number (the number of tiller which began to grow after defoliation) of stubble at the time of defoliation in all grasses. And as the results of these, the regrowth after defoliation was affected in these grasses.

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1) Italian ryegrass and Dallisgrass were used in this experiment to clarify the effect of top-dressing of nitrogen on the regrowth of herbage plants. 2) Effect of topdressing of nitrogen at the time of defoliation appears soon after treatment. Regrowth-tiller number and regrowth of herbage plants in topdressed plot were more than that of non treated plot. 3) There was close relation between the amount of nitrogen topdressed on the 14th day before defoliation and the regrowth of herbage plants. It was recognized that the more the nitrogen, the more were the tiller number, regrowth-tiller number of stubble and the regrowth of herbage plants.

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