The sporulation process was observed in timothy eye spot fungus, Heterosporium phlei GREGORY. 0.5ml of spore suspension was poured on to the surface of V8-juice agar in a petri dish with a sterilized Komagome pipet. Sporulation was observed to initiate 36 hours after the pipetting (Plate II). Sporulation increased rapidly between 48 and 60 hours (Fig.1). Morphologically uniform spores were available 5-6 days after the pipetting (Fig.2). The suspention was consisted of 45-55% of one septate spores, 15-20% of spores with no septa, about 20% of two septate spores, and about 10% of three septate spores (Table 1 and Fig.2). Spores were the larger in size and extruded the more germtubes as the number of septa increased. While the number of germtubes per cell decreased as the number of septa increased. Attached conidia germinated easily in damp air (Plate 1). The formation of the first and the second conidia was observed microscopically (Plate 3).

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A series of experiments was carried out to compare the various methods for determining the forage intake of grazing animals. Two Hereford heifers were used in the following trials. Trial 1: During the 11-day trial period, the heifers remained in their respective stantions and were supplied with freshly harvested green forages. The animals were given 10g of chromic oxide in a gelatin capsule twice daily, at 8a.m. and 4p.m. Total fecal collections were made manually. Chromogen contents of the green forages and feces were determined by the usual method. The fecal samples were dried and analyzed for chromic oxide. Two indicator methods, chromogen and chromogen-chromic oxide method, gave good estimations of forage intake (Table 1). Trial 2: When the heifers were confined to a pasture, forage intake was determined by these indicator methods. The value estimated by the chromogen-chromic oxide method showed close agreement with that by the chromogen method (Table 1). Trial 3: The chromogen-chromic oxide method and a forage meter, an electronic capacitance meter for estimating forage yields, were used to estimate the forage intake of the grazing heifers. The forages intake estimated by the forage meter was comparable to that by the indicator method (Table 2). The correlation coefficient between these estimated values was 0.61 and was statistically significant at the 5% level. In view of the result it seems likely that the forage meter can be used for estimating the forage intake of grazing animals.

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Assesments of palatability (measured as mean % herbage consumed by sheep) were made at 7 grazing times on 11 orchardgrass varieties. At the same time, some chemical components were analysed at each grazing time. Chemical component percentages of each variety were compared with the mean of 11 varieties. Then the relationship between chemical components and palatability were examined. Total soluble carbohydrate (TSC) percentage was high in "Hera" and "Pennlate", and low in "S143" and "S345" at almost all grazing times. Crude protein (CP) percentage of "Chinook" increased gradually from spring till fall. Contrarily, that of "S143" and "S345" decreased. Crude fiber (CF) percentages were generally high in "S345" and low in "Pennlate". CF percentage of "S143" increased gradually till fall and that of "Chinook" decreased. Though the varietal variation of in vitro digestibility (IVD) was small, the difference between the highest "Hera" and the lowest "S143" was 4.4% when these varieties were compared using the mean of 7 grazing times. Correlation coefficents between palatability and some chemical components were getting higher after the 5th grazing (middle August). Significant positive relationships were obtained in a combination of TSC and of IVD and palatability. Significant negative correlations were obtained in a combination of CF. However, satisfactory correlations were not established in a combination of CP. Multiple correlations palatability were calculated in a combination of two components among TSC, CP and CF. As a result, the combination of TSC and CF is expected to be the best predicition of palatability for orchardgrass varieties.

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In a previous paper, authors classified alfalfa varieties (Medicago sativa L.) into five groups according to their growth habits. Our present paper is a report of investigation on the growth habits of each group in its ecological aspect. In the experiment 59 varieties were used for materials. The comparative study of five groups on the multiple correlations among daylength, temperature and plant height throughout various growing periods between cutting dates in the natural environment for three years starting from 1965 was conducted. The results were as follows: 1. The simple correlation between plant height increase per day and daylength was 0.820 and the simple correation between plant height and temperature was 0.590. From this, it is confirmed that alfalfa is affected quite sensitively by daylength, and temperature is a secondary factor. 2. As to the simple correlations between daylength and plant height among the groups, 0.714 (lowest) was for group I and about 0.84 for the group IV and V. The correlations for the group V tended generally to exceed that for group I. Varieties of the group I originating from the low-latitude region were insensitive to daylength. On the other hand, varieties of the group IV and V originating from the high-latitude were very sensitive. 3. The resting period and the critical time for fall harvest were estimated through the photothermograph at the experiment station. As varieties of the group V had three months of dormant period, such group might not be utilized after about Oct.20 for fall harvest. In varieties for the group I, the dormant period was very short and the fall utilization might be possible up to about Nov.20. The utilization period of such group could be longer by one month than the group V. 4. The critical daylength for alfalfa dormancy in winter period was between 9.2 hours for the group I and 10.4 hours for the group V, judging from calculation through the regrssion on plant hegiht and daylength. The limit temperature to the fall dormancy was between 6.9℃ for the group I and 13.6℃ for the group V. From the above results, it is concluded that great emphasis should be placed on photoperiodic factor rather than temperature factor in alfalfa cultivation. Moreover, it is also concluded that varieties of the group I and II with high ecological adaptability to the warm region should be used for cultivation in the south-western warm region in Japan.

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This experiment was conducted to investigate the differences among grasses in the growth of primary tillers in early stage after their appearance. Grasses used were tall fescue, cv. Kentucky 31, orchardgrass, cv. Frode, and Italian ryegrass. The plants were grown at 12°, 20°, and 28℃ under long and short daylengths, respectively. The results are summarized as follows. (1) Number of leaves of primary tillers and rate of increase in the number were largest in orchardgrass, followed by those in Italian ryegrass and those in tall fescue were smallest. (2) Fresh weight of tops of primary tillers was largest in Italian ryegrass at 12℃ and 20℃, while at 28℃ in orchardgrass. That in tall fescue was smallest at all the temperatures tested. Increase in number of secondary tillers in Italian ryegrass was more remarkable than that in tall fescue or orchardgrass. These results indicated that the growth of tops of primary tillers, as shown by the fresh weight and the number of secondary tillers, was most remarkable in Italian ryegrass, followed by that in orchardgrass and that in tall fescue was not remarkable. (3) The growth of roots of primary tillers, as shown by fresh weight, number and length were most remarkable in Italian ryegrass, followed by that in orchardgrass and that in tall fescue was not remarkable. From the results mentioned above, it was shown that ecto-morphological form of primary tillers in Italian ryegrass was established early, followed by that in orchardgrass and that in tall fescue was latest. It may be suggested that time of independence of tillers from main stem differs with grasses.

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This experiment was conducted to investigate the effect of elongation of main stem and removal of the stem on appearance of new tillers and heading. Grasses used were orchardgrass, cv. Frode, tall fescue, cv. Kentucky 31, and Italian ryegrass. The results are summarized as follows. 1) In orchardgrass, appearance of new tillers was inhibited during the elongating stage of main stem. Removal of the elongating main stem resulted in increase in the numbers of new tillers and heads. The increments were large in the early stage of its elongation. After heading of the main stem, however, there was no effect of the removal. 2) Appearance of new tillers in the grasses tested was inhibited during the elongating stage of main stem. The inhibition was most remarkable in tall fescue, followed by orchardgrass and Italian ryegrass. 3) Removal of the elongating main stem resulted in increase in the numbers of new tillers and heads. The increments were largest in tall fescue, followed by orchardgrass and Italian ryegrass. From the results mentioned above, it may be suggested that degree of apical dominance and competition of nutrient absorption among tillers varied among different grasses.

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The purposes of this experiment are to measure the chemical composition of actually grazed herbage and to determine the relationship of herbage intake to the chemical composition of herbage when Holstein steers are grazed on orchard grass dominant pasture. DM intake of grazing steers was determined by a herbage-cutting technique. The chemical composition of the grazed herbage was estimated from the difference between the chemical composition of the whole herbage in protect cage and that of the residual herbage after grazing. The grazed herbage was higher in crude protein (p<0.01) and ether extract (p<0.05) and lower in NFE (p<0.01) than the whole herbage. There were significantly positive correlations between all components of the grazed and the whole herbage (p<0.01). These results indicated that chemical composition of the herbage, actually consumed by steers, was different from the composition of the sward, but the composition of the grazed herbage was influenced substantially by the composition of the sward. DM intake of grazing steers was negatively correlated to crude protein (r=-0.690), ether extract (r=-0.690), crude ash (r=-0.517) and CP/NFE ratio (r=-0.746) of the grazed herbage, and was positively correlated to NFE (r=+0.629) of the grazed herbage. Furthermore, the rumen NH_3 concentration of steers was negatively correlated to DM intake (r=-0.581) and to NFE of the grazed herbage (r=-0.674) and positively correlated to crude protein (r=+0.659) and CP/NFE ratio (r=+0.706) of the grazed herbage. These results indicated that herbake intake of grazing steer on orchard grass dominant pasture was influenced by the chemical composition of the herbage, especially crude protein and NFE contents, and that the rumen NH_3 concentration was also influenced by these two components of the herbage and might affect the herbage intake of grazing steers.

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How the amount of fertilization and cutting frequency affect the dry matter and crude protein yield of available herbage on Miscanthus sward have already been reported under the title, "Comparison of Productivity between Semi-natural Miscanthus Sward and Improved Orchard grass- Ladino clover Mixture." The following is the summary of the study results on some effects of fertilization and cutting on the kinds of herbs that constitute the yields of the Miscanthus sward. 1. The total number of species that appeared in each plot decreased gradually in 1-cutting plot, but increased in both 2-cutting and 3-cutting plots. 2. The total dry matter yields in each plot decreased as the cutting frequency increased, but increased as the amount of fertilization increased. The dry matter yields of the following species decreased as the cutting frequency increased: Miscanthus sinensis, Lespedeza bicolor, Lysimachia clethroides, etc., while those of the following increased: Pteridium aquilinum, Arundinella hirta, Carex caryophyllea, Carex humilis, Calamagrostis hakonensis, etc. Number of shoots of Miscanthus sinensis and Lespedeza bicolor decreased by cutting, while those of Pteridium aquilinum increased, particularly significant in 2-cutting plot. 3. Percentage of bareland was smaller in plots with a higher cutting frequency. This was due to an increase in bottom grasses. 4. The dry matter yields of herbs with low palatability mainly of Pteridium aquilinum was the greatest in 2-cutting plot, being followed by 3-cutting and 1-cutting plot in order 3-cutting plot. 5. The one-cutting produced the greatest yields of dry matter, which, however, was low in feeding value. In 2-cutting plot the production of unavailable species increased. It may be concluded that taking both the palatability and the forage value into consideration, the 3-cutting is the most advantageous of all.

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Maximum crop growth rate was compared among the four clones of Italian ryegrass of which leaves are different internally in the level of chlorophyll content based on leaf area. The four clones were selected from the variety 'Nakei No.4' and named as the clone Green 2 (G2), Green 1 (G1), Yellow 2 (Y2) and Yellow 1 (Y1) according to their chlorophyll content. The contents were 6.6, 5.8, 3.8 and 3.0mg (a+b)/dm^2 on leaf area basis in the plants grown late in winter before the beginning of the experiment. The tillers of each clone were increased enough to cover the experimental field of 100m^2 per clone and were transplanted at three densities (Low:50×50, Mid.:25×25 and High:12.5×25cm^2 for space per unit stubble, respectively) in middle September on fertile soil with high level of fertilizer application. Plots were arranged by split-plot design with two replicates. Dry matter increase in both the above- and underground organs of the pure clonal sward was measured with six replicates at the intervals of 7-10 days in three times of samplings (sampling I, II and III) during the most prosperous period from middle of April to middle of May, since the period might cover satisfactorily the 'optimal' LAI stage of every sward. The maximum crop growth rate, the optimal LAI and Chlorophyll Index for each of the clonal canopies in the three density plots were determined. The net assimilation rate at the optimal LAI was compared by analizing into the following elements shown as the next equation ; NAR=(a-r)-r_n・SLW-R・(C/F)・SLW…(Equation (3) in OKUBO et al., 1975a) 1. Optimal LAI ranged widely from 6 to 11 and optimal Chlorophyll Index (CI) varied more from 2.4g/m^2 to 8.4g/m^2 (Table 2, Table 3). Much variation in chlorophyll content on leaf area basis (Ch_A) was observed-the maximum 6.6-6.9mg(a+b)/dm^2 in the clone G2 and the minimum 2.5-2.8mg(a+b)/dm^2 in Y1. The range of the optimal LAI showed a wider tendency in the sward of the clone having higher level of Ch_A than in the clone of lower Ch_A (Table 3). 2. The values of the maximum crop growth rate ranged widely among the clones from 27-35g/m^2/day in G2 to 9-18g/m^2/day in Y1 on average for three weeks. Those variations depended fairly on optimal CI but little on optimal LAI (Fig.1). This fact was due to the dependence of the net assimilation rate at the period of the optimal LAI upon the levels of Ch_A of the clones (Fig.2 and Table 4). 3. Net assimilation rate on chlorophyll weight basis (E_c) in sward condition varied with density to some extent. But the E_c showed approximately the same value among the clones i.e. 6-7g/g/day at the lowest level of density and 3-5g/g/day at the highest and middle density. 4. The sward of the clone having a higher Ch_A in the surface leaves on a canopy showed a higher Ch_A also in the lower leaf layer, especially as in G2, compared to the clone with lower level of Ch_A as in Y1, at the stage around optimal LAI (Table 5). 5. It can be safely inferred that the dependence of variation in maximum crop growth rate upon Ch_A would be mainly due to the difference in photosynthetic activities of sward leaves as far as in these swards of the four clones concerned above. The photosynthetic activity would be affected first by chlorophyll content per unit of leaf area on leaf weight relating to 'weak light factor', second by specific leaf weight, cell size or some other factors, and third by some ability to maintain the Ch_A as high as possible even in the shaded leaves situated in the lower layer of a canopy on high level of LAI.

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The changes of the nutritive value and dry matter yield of corn plants with stage of maturity was investigated for 50 days from September to October in 1974 in Hokkaido prefecture. Corn plants used in this experiments were three varieties such as HEIGENWASE, KO-No 8 and GIANTS. In relation to above experiments, the investigation of the nutritive value of corn silage was carried out by detailed analysis of carbohydrates. Corn silage used in this experiments were 15 samples, from early milk to glazed stage of maturity prepared from 7 corn plants, and carbohydrates analysis was done to total carbohydrates, mono-oligo saccharides, starch and structural carbohydrates. Dry matter yield was held constant from the end of September, but percent of grain in whole plant dry matter was increased subsequently in three varieties. Change of TDN contents which was predicted by laboratory method was not exceed 10% for 50 days of experimental period. In 15 silages, mean value±standard deviation of crude protein, crude fat, lignin, total carbohydrates, mono-oligo saccharides, starch, structural carbohydrates contents of silage dry matter and total carbohydrates contents in organic matter were 9.1±1.1, 3.2±0.6, 3.8±0.7, 77.8±1.8, 2.2±1.6, 15.0±8.4, 60.6±7.2 and 82.9±1.2% respectively. TDN contents of 15 silages were widely distributed from 60.7 to 73.1% and contents of digestible carbohydrates strongly influenced the TDN contents more than digestible crude protein or digestible crude fat. There was high negative correlation. (r=-0.91, p<0.01) between the contents of digestible non-structural carbohydrates (mono-oligo saccharides and starch) and digestible structural carbohydrates.

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The growth, yield and nutritive value of silage were compared between early varieties of corn (Heigenwase, Hokuyu) and late varieties (Ko No.8, Giant) cultivated in Tokachi district Hokkaido. (1) A significant difference in the ratio of grain component in the total dry weight was observed between early varieties and late varieties of corn plant ; 60.9% for Heigenwase, 47.3% for Hokuyu, 31.6% for Ko No.8, 20.6% for Giant. (2) The quality of chemical score on silages of early varieties markedly exceeded that of late varieties. (3) Dry matter digestibility of early varieties was higher than that of late varieties, difference being from 7% to 10%. (4) TDN and DE content in Heigenwase, Hokuyu, Ko No.8, Giant ranged ; for TDN ; 69.4-71.6%, 67.0-70.7%, 62.1-62.6%, 60.7-60.9%, and for DE ; 3.12-3.16 Kcal/g.DM, 3.14 Kcal/g.DM, 2.90-2.93 Kcal/g.DM, 2.69-2.89Kcal/g.DM, respectively. (5) The yield of TDN per 10a in Heigenwase was 655 kg, Hokuyu was 736kg, Ko No.8 was 710kg, Giant was 621kg, respectively. The yield of digestible crude starch per 10a was greater in early varieties than in late varieties. The yield of dry matter in late varieties was higher than in early varieties, but the latter have a possibility of increasing TDN, DE and DDM yield per 10a up to the level of the former by dense spacing of plants.

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The six cool temperate grasses had been grown under mimic grazing system for six years on field plots treated with 2 levels of fertilizer supply respectively. From the data obtained above, seasonal fluctuation of dry matter production was mainly examined in relation to occurrence of summer depression using statistical method. The results obtained were as follows: 1) It was recognized that occurrence of summer depression of each species was closely related to elevation of temperature in previous regrowth period and increase in total precipitation during rainy season. 2) Much closer relation between its occurrence and two factors was shown in all plots treated with higher supply of fertilizer and the extent to which each species was affected by two f actors decreased in the order as follows: Orchardgrass>Perenial ryegrass>Red top>Tall fescue>Kentucky bluegrass. 3) In plots treated with lower supply of fertilizer, only Perenial ryegrass and Orchardgrass which were considered to be less resistant to the summer depression showed the same relation as mentioned in 1), but the extent affected by two factors was much less than that in case of 2). 4) Above two factors did not affect to each species at the same rate. For instance, Perenial ryegrass was severely affected by both factors, but Red top was more likely to be affected by temperature than precipitation. It was concluded that precipitation during rainy season was recognized to be one of the important factors which induced summer depression, added to high temperature, drought, diseases and insects which had beeh considered to be main factors of its occurrence.

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This paper deals with the most suitable utilization pattern of deposit rearing by the utilization of public grassland on the basis of following problems, i.e. 1) what is the factor controlling the deposit percent of individual dairy farming management, 2) the examination on economic effect of deposit to public grassland, namely i) comparison of cattle rearing cost between deposit and domestic rearing, ii) the examination of effect on the agriculture income enlargement in the case with separation of rearing section from dairy farming management, and 3) the examination on the hopeful way of deposit in order to obtain the highest earning power of individual management. The field for research object was Kamishihoro town under the Tokachi Branch Office of Hokkaido, and the research was performed for 5 years from the 44th to the 48th of Showa. The results of research are shown in the following. 1. It was recognized that the primary factor affecting the deposit percent is the area of pasture per one head of adult cattle and the deposit percent is elevated with decrease of the area. But, the statistic significant difference could not be obtained with other factors. 2. (i) Domestic rearing cost (for 7〜28 months old) tends to decrease gradually with the increase of scale of rearing cattle heads. And, the rearing cost under the class of 15 rearing cattle heads is higher than the rearing cost in the case of deposit to pasture and the deposit rearing is more favorable from the view of rearing cost. And from the view of seasonal rearing cost the rational rearing way of cattle is the deposit rearing in the pasture in the summer season and the adaptation to change it into the domestic rearing in the winter season. (ii) The effect of income enlargement with dairy farming management in the case with separation of rearing section can be recognized in any case of management, but there is the difference in its degree by the management condition. 3. In order to elevate the earning power of dairy farming management, it is most desirable to utilize the public grassland completely and deposit the rearing cattle to it and to become the management of major milking. Namely, in respect to delivered rearing cattle, the total cattle, heads of months suitable as the deposit object are deposited through all the year. And, it is favorable to increase the heads of milking cattle within the area of occupying grassland (40 ha by this trial balance). It is the case in which the inheritor is reserved in the management and the others are for sale individually.

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[in Japanese]

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