In order to establish proper method of harvesting seed of Green panic (Panicum maximum var. trichoglume), an experiment was conducted to clear the processes of the heading, seed ripening and shattering in this grass. 1) The maximum rate of heading was observed at about 3 weeks after the heading began, and before this time large-sized heads almost emerged (Fig.2). 2) A survey of the blooming pattern in a head was carried out. The blooming occurred night ; starting from 9 p.m. and most frequently until 11 p.m. (Fig.3). It started from the uppermost spikelet in a head, and from the uppermost floret in each spikelet and proceeded downward. The blooming was kept up for about 7 days per head, and lasted for about two hours per floret. 3) On the 9th day after the blooming started in a head, the shattering of the florets was first observed, and on the next day (10th day) it increased up to 30% of the total florets in a head. Although the shattering did not occur in a few days thereafter, it increased rapidly again (Fig.5). The former heavy shattering until the 10th day after the blooming seems to be affected by the climatic conditions, especially such as rain and wind (Fig.4), but the latter increase might be inevitable in the ripening process (Fig.5). 4) Seeds thinner than 0.50mm were not able to germinate, and in case of seeds thicker than 0.51mm, the thicker seeds showed the higher rate and percentage of germination (Fig.6). These results could suggest that when the seed crop is harvested from large-sized heads which constitute the first maximum rate of heading and when the seed shattering proceeded to about 30% loss of the whole florets, the highest seed yield of good quality will be obtained.

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Symbiotic nitrogen fixing activity of Ladino clover during the course of top recovery after cutting were determined by acetylene reduction method. Results obtained are as follows. 1) Acetylene reducing activity (ARA) in Ladino clover decreased severely when top of the plant was cut. The degree of the decrease in ARA clearly corresponded to the strength of the cutting. The minimum value of ARA appeared on 2 days after cutting. 2) ARA in regrowing Ladino clover increased with the progress of recovery and the value of ARA of the recovered plant attained nearly the same level as that of uncut plant on 26 and 16 days after cutting when expressed by per whole plant or unit fresh weight of the underground part of the plant respectively. 3) Decrease in illumination resulted in the decrease of ARA and the effect of illumination was severer in recovering plant than uncut plants. 4) ARA in Ladino clover didn't show clear diurnal variation. But darkness resulted in the decrease of ARA and the effect of darkness was soften by foliar application of sucrose.

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This investigation aims to disclose the effect of sucrose on nodule formation and nitrogen fixation as directly as possible. Isolated roots of mung bean were grown for 25 days under aseptic conditions using modified Raggio's excised root culture method in which orga nic nutrients including sucrose are fed to the cut end of the excised root while the root tip are grown in mineral nutrients medium inoculated with rhizobium. After that, the activity of nitrogen fixation capacity on the cultured roots was measured by acetylene reduction assay. The results obtained were as follows. 1) There existed remarkable effects of sucrose on growth, nodulation and nitrogen fixation capacity of the excised roots. Moreover, it was shown that the optimum concentration of sucrose for the activity of nitrogen fixation capacity was remarkably higher than that for the growth and the nodulation of excised roots. 2) Increasing the concentration of sucrose in medium, the activity of nitrogen fixation capacity per unit fresh weight of roots and per unit number of nodules increased gradually. It was strongly suggested from this experiment that the activity of nitrogen fixation capacity was directly activated by the supply of sucrose.

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The seasonal pattern of the productivity of pasture established on the clayey soil is very different from that of the ando soil. The productive pattern of top and root or the growth analysis on the basis of relative growth rate, net assimilation rate and crop growth rate of orchardgrass in cold upland have been already reported by many workers. However, their result are not necessarily in accord with each other, especially, on the part of under ground. In the mixed pasture, the productive patternof a mixed population composed of different grass species such as orchardgrass, Italian ryegrass and ladino clover is likely to change due to various factors. Moreover, the occurrence of annual weeds in a large bulk, for example, Echinochloa crusgalli, Setaria viridi, Digitaria adscendens, D. violascens, Amaranthus retroflexus, A. blitum and Achyranthes japonica from early summer to autumn in clayey soil pasture have been complicated the problems to be clarified about the productive pattern of pasture in warm-temperate zone of Japan. Thus, we have taken this report for the purpose of learning basic knowledge for prediction of dry matter production in a mixed pasture in warm-temperate zone of Japan. First of all, in 1970 and 1971, the experiments on the seasonal productive pattern and net production of mixed pasture have been conducted at the experimental farm, Kobe university. Secondary, in 1974 and 1975, the additional experiments on the problems mentioned above are carried out at the experimental farm, Nagoya university. The experimental results obtained are summerized as follows: 1) Orchardgrass, Italian ryegrass and ladino clover belonged to the cool season type decreased outstandingly in the dominance from July to September. The site occupied by these cool season plants until now was invaded immediately by annual weeds belonged to the warm season type. The ratio of the yield of annual weeds in the total yield of the experimental pasture was shown nearly 50% in a year. Especially, the maximum percentage of the ratio reached. 90% or more in September. 2) The weight of stubble at the high level fertilizing plot (N 40kg, P_2O_5 20kg, K 40kg per 10 are) was higher than that of the low level fertilizing plot (N 20kg, P_2O_5 10kg, K 20kg per 10 are). In the case of high cutting frequency, the ratio of stubble to top in weight increased gradually from summer to autumn. The ratio was about 20% over a year, excepted for midsummer and late autumn. On the contrary, the ratio decreased gradually from summer to autumn in the case of low cutting frequency. It was considered that the invasion of the annual weeds seemed to affected the growth of the stubble, although the reasons for the progress could not simply explained with only soil factor as a soil texture. 3) The productive pattern of the roots and the rhizomes during a year in orchardgrass pasture in warm-temperate zone is very different from that in cool-temperate zone of Japan. The similar phenomenon was recognized in the mixed pasture. They had several decreasing periods in the weight and were two times or more at least, namely June and October. It seems to be affected by years after establishment, single seeding or mixture seeding, cutting frequency and level of fertilizing to pasture. 4) The production of the roots and the rhizomes in the clayey soil pasture was lower than that in the ando soil pasture. 5) The accumulation of the litter during a year in mixed pasture in warm-temperate zone of Japan was recognized 200-270g per meter square. 6) The net production of high level fertilizing plot and low level fertilizing plot in the mixed pasture were 2003g and 1740g per meter square, respectively.

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Most of the native grasslands in this country grow to the Zoysia-type of vegetation when continuously grazed by animals for years. Seasonal changes in dry matter production and efficiency of solar energy conversion of the Zoysia-type grassland were determined from the spring of 1972 to that of 1974. The grassland examined lies at the hillside of Mt. Nanashigure located near to Morioka city, Iwate Prefecture. Dry matter in both above- and under-ground organs of Zoysia plant and surface litter were harvested monthly from May to October in terms of growth analysis during one-year protection from grazing. Results are as follows. 1. Total dry weight of both the above- and the under-ground organs of Zoysia sward was high in the lower area of a slope of the grassland mostly in every season, but the seasonal trends were nearly the same among the stands of three places examined of higher, middle and lower areas of the slope. The dry weight of surface litter also showed nearly the same pattern as that of standing crop in changes with season and with the place of a slope (Fig.1). 2. The highest value of total dry matter (V_1〜V_5) of the Zoysia sward was seen in October (Table1), while that of the rate of growth (V_1〜V_5) in the period from June 10 to August 9 (Table 3). Among plant parts of Zoysia, the growth rate of erect stalks (V_2) first attained the highest value in the year during June and July following the decrease in dry weight of stolon (mostly growing below ground level as like as rhizome, V_3), that of leaves (V_1) did second during July and August and that of stolon (V_3) increased mostly from August to September. The rate of root increase (V_4) was not so much but it was rather high in spring. That of surface litter (V_6) decreased month by month excepting the period from early July to early August just after rainy season (Table 3). Most of the seasonal variation in the total dry weight was due to those in the leaves and erect stalks. Less variation was observed in those of stolon and root than in those of leaves and stalks but over the 60 percent of the total dry matter weight of Zoysia plant was composed of stolon and root in every season (Table 4). 3. Efficiencies of solar energy utilization (E_u) against total radiant energy (0.3〜4.0μ), calculated on monthly average from the growth rate data (Table 3) and the heat of combustion per unit dry weight (Table 5), ranged from 0.22% in spring to 0.62% in midsummer and decreased in autumn. The efficiency calculated for the herbage available only (E_u in HA) ranged from 0.24% in spring to 0.49% in midsummer (Table 6). The heat of combustion of Zoysia plant per unit dry weight was a little higher than those of temperate grasses measured by Okubo et al. (1969). The annual average efficiency in living whole plant growth was 0.10%, that for the growing period 0.23%. 4. From the seasonal variations in the total dry matter weight and in the fall of standing dead estimated from surface litter balance in terms of litter bag method, the annual net production was calculated by use of the equation in Table 9 (notes). The annual net production of the Zoysia-type grassland examined here was estimated as 531g/m^2/year. This value of net production was approximately corresponding to 1.5〜1.6 times as large as that of standing crop above-ground (Amax, that is, leaves and erect stalks) without standing dead. The annual conversion efficiency was 0.24% when the fall of standing dead was taken into account for the net production of the grassland.

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Sasa-type of semi-natural grasslands widely distribute in Japan, and have been used as grazing or meadow pastures. Though it differs very much from temperate forage grasses in growth pattern, there are few reports about dry matter production in Sasa community. The. purpose of the present paper is to clarify the growth pattern of Sasa community by measuring its seasonal changes of dry matter production. The authors also intend to determine the parameters for the mathematical model of energy flow of the grassland ecosystems reported previously. This investigation was carried out in the nearly pure community developed around the larch grove located in the hillside with 800 meter altitude within the Shibahara Branch of Fukushima Livestock Station in 1975 and 1976. Results obtained are as follows ; 1. Aboveground part (A) attained its maximum weight (745, 883 DM g/m^2) in June in 1975 and 1976, respectively, then descended slowly towards autumn. Underground part (U) decreased the weight from spring to summer, then it recovered the weight again. As the results, seasonal changes in total standing crop (P) in Sasa nipponica community ranged to 1228-1828 and 1651-1953 DM g/m^2 in 1975 and 1976, respectively (Table 1). 2. Dry matter increase of whole plant (mean CGR) was accelerated in spring and autumn. It attains 10-15g/m^2/day. It was clarified that the peak of mean CGR in spring was brought by the rapid increase of aboveground part, while that in autumn was brought by the filling up of aboveground part (Fig.2). 3. Leaf area is thin at the beginning of growing season, and attains to LAI 5-6 in July. But only less than half of these leaves overwintered (Table 4). 4. According with the development of current foliage (F_c) from June to July, wintering foliage (F_w) was falling down immediately. However, current culm (C_c) almost complete its development by the early in June, and wintering culm (C_w) decrease its numbers gradually towards autumn (Table 5). 5. The maximum Top/Root ratio of around 1 was observed in July when the aboveground part grew thick upmost and the underground part supremely waste away (Table 7). 6. Considering from the growth pattern and amount of storage substance in rhizome, it may agreeable to have start grazing around the end of summer when the underground part complete its filling up.

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In the previous paper, the authors investigated about dry matter production in Sasa nipponica community. In the present paper, seasonal changes in heat combustion value and nitrogen content were further investigated to clarify the dynamics of nitrogen and energy in Sasa-type grassland ecosystems. Samplings of Sasa nipponica plant materials were carried out monthly in 1975 and 1976 from those of the dry matter production measurements in the former report. Materials separated into each organ were dried and ground, then preserved in deccicater until the analysis. Results obtained are as follows ; 1. Mean nitrogen contents of whole plant (P) were observed around. 0.5 to 0.7% throughout the year. The content of aboveground part (A) always exceeds in that of underground part (U). Just developed current foliage (F_c) contained the highest nitrogen content as much as 2% but went down to around 1% by the winter. Wintered foliage (F_w) kept nearly 1% of nitrogen content until it defoliate in summer or autumn next. The value becomes smaller in the order, foliage (F), litter (L), aboveground standing dead (D_a), underground part (U), culm (C). Seasonal change in nitrogen content of underground biomass (B_u) has small peaks in spring and autumn, but it went down as small as 0.4% during summer when above-ground part grow most luxuriantly. Current culm (C_c) contented considerably high nitrogen in spring, but it kept constant value of 0.3% for about one year (Table 1). 2. Total nitrogen amount per unit ground area in Sasa nipponica community has peaks in June (11.27g/m^2) and September to October (11.09-11.73g/m^2). It suggests that the former peak was brought by the increase of nitrogen at the aboveground part, while the latter was brought by the filling up at the underground part. It seems that the seasonal changes of nitrogen amount in one plant part are considerably owing to the translocation of nitrogen from the other part (Table 2). As the results, in early spring and late autumn, more than 60% of the total nitrogen is stored in underground organs (U), while as much as 2/3 of it distributes at aboveground organs (A) during summer (Fig.1). 3. Mean heat combustion value of whole plant per unit dry weight was ranged from 4340 to 4590 cal/g throughout the year. Underground part (U) surpassed above-ground part (A) in heat combustion value. Among aboveground organs, heat combustion valus becomes smaller in the order, current foliage (F_c), culm (C), wintered foliage (F_w), aboveground standing dead (D_a), litter (L). There was no sigificant difference between current culm (C_c) and wintered one (C_w) (Table 3). 4. Total heat amount per unit ground area of Sasa nipponica community was ranged from 7200-8500kcal/m^2 throughout the year. Same as the seasonal change of dry matter distribution, as much as 70% of heat amount of whole plant is stored in the under-ground organs (U) in early spring and late autumn, while more than half of it scatters at the aboveground part (A) during summer (Table 4, Fig.2). 5. It is observed that in young organs taking an active part, both nitrogen content and heat combustion value are high but generally decline according with the advance of senescence in the organs. 6. Comparing the pattern of distribution of nitrogen and heat amount in Sasa nipponica community, the heat amount inclined to distribute in underground part, while the nitrogen amount in generally exceeded in aboveground part.

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Chemical characteristics of ladino clover saponin were studied in relation to the assay [figure] [figure] method by the densitometric TLC. The saponin was isolated from freshly cut ladino clover by 95% ethanol extration, concentraction and direct precipitation procedures. Purities of crude saponins and crystalline ones were determined. The purification with an acidified butanol was satisfactory to decrease the ash contents of the saponin. TLC of the crystalline saponin has indicated that this method separates the co-existing fluorescent substances except one from the saponin, the saponin is primarily consisted of at least two saponins, and the development with a butanol-ethanol-1N ammonium hydroxide mixture produces a compact spot being preferable to the densitometry. Quantitative determination of ladino clover saponin was achieved by the densitometric TLC. Instead of measuring peak areas, the scanogram peaks were cut from the recorded paper and the cuttings were weighed. It was shown that a linear relationship exists between the weight of saponin applied and the logarithm of cutting's weight of scanogram peak derived from the spot produced.

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Ladino clover sapogenin was prepared from the crystalline saponin by the acid hydrolysis. The sapogenin was solely neutral one. Further fractionation divided the material into two sapogenins. The sapogenins I and II were decided from their chemical characteristics to be identical with sapogenols B and C previously cited by other researchers. GLC of TMSi ethers of the sapogenin mixture gave two peaks with the retention times of 15.3 and 31.2. The peaks were identified with each of the TMSi ethers of sapogenins I and II, where by the faster peak was derived from sapogenin II and the later from sapogenin I. A method for quantitative determination of the ratio of sapogenins I and II in mixtures was described.

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A simplified in vitro rumen procedure for the determination of digestibility was proposed. The method was developed on the basis of Van Soest method, in which the acid pepsin treatment of Tilley and Terry method was replaced by a cell-wall determination using the neutral detergent procedure. In this instance, laborious manipulations were necessary to transfer the contents of the incubation glass tube to a container for refluxing with 100ml of the neutral detergent solution. In the simplified method, on the other hand, 20ml of the neutral detergent of 5 times concentration which contains the solutes in equal amounts with 100ml of the solution which used in the ordinary procedure, 1ml of decalin and 0.3g of sodium sulfite were added directly into the incubation tube and the tube was boiled for 1hr in a waterbath. The digestibility of three forages were determined by Tilley and Terry method, Van Soeat method and the simplified method, respectively. Standard deviations of the means obtained by the simplified method were a little larger than Van Soest method, but smaller than Tilley and Terry method. Highly significant correlation was observed between the obtained values by the simplified method and by Van Soest method in respective nine species (r=0.998, P<0.01). Comparing those methods, it was found that the simplified method required less time and fewer manipulations and gave digestibility with a high accuracy. It may be concluded that this method will be of aid to plant scientists who want to know the digestibility of many samples at a time.

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The nutritive value of Heigenwase corn plant was investigated during the periods from silk to over ripening stage. Digestible dry matter obtained by cellulase method varied from 64 to 68 percent and the percent of digestible corn grain in digestible dry matter varied from 10 to 71 percent. The crude protein contents decreased gradually with the developing maturity until the dent stage and showed constant value, approximately 7 percent after the dent stage. The percent of cereal protein in total protein of whole plant increased gradually and the value rised to more than 70 percent in the over ripening stage. Silages were pre pared in three stage of maturity such as dough, ripening and over ripening and digestion trials were carried out by sheep. TDN contents of the ripening stage showed the highest value in three silages. In two silages of ripening and over ripening stage, DCP contents were under 3.0 percent.

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