Fine surface structure of seed coats of ten leguminous forage crop species were observed through scanning electron microscope under 10 to 25kV. Species tested were Glycine max, Lupinus luteus, Vicia villosa, Trifolium subterraneum, Trifolium incarnatum, Trifolitm hybridum, Medicago sativa, Astragalus sinicus, Trifolium pratense and Trifolium repens. Various types of wax-like extrusion were observed on the surface of seed coats and they were classified into five groups according to their shape and supposed thickness as follows; 1. Thick cover: Glycine max, Trifolium hybridum, Trifolium repens, Astragalus sinicus 2. Scab: Trifolium subterraneum, Trifolium pratense 3. Brickrange: Trifolium incarnatum, Medicago sativa 4. Rosary: Vicia villosa 5. Reticulate: Lupinus luteus The shapes and positions of hilum, raphe and micropyle were described as well with reference to the site of imbibition when germinated.

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Heritability for the digestibility of orchardgrass was estimated under the management of two annual cuttings. From 511 orchardgrass plants derived from Hokkai -1, -2, -3, -4, -5, -6, -7 and Kitamidori, 5 HDC (high-digestibility clone), 6 MDC (medium-) and 6 LDC (low-) plants were selected based on the digestibility by the one-step cellulase method (SAIGA & HOJITO, J. Japan. Grassl. Sci., 23, 177-182, 1977) for the aftermath in 1975 (Fig.1 and Table 1). Four HDC, 5 MDC and 5 LDC parent plants of each group were pollinated in isolated conditions. Digestibility of parent and offspring plants was estimated at the aftermath in 1978 and the first growth and the aftermath in 1979 (Table 2, Fig.2 and Fig.3). No differences between MDC group and LDC group were observed both in parents and in offsprings at all cuttings. However, significant differences were obtained between these groups and HDC group in the aftermath of 1978 and 1979. Realized heritabilities (hBN^2) estimated by the comparison of HDC with MDC and LDC were 0.60, 0.57, 0.48 and 0.42. Another three HDC, MDC and LDC plants were pollinated to 6 MS (male sterile) plants in all combinations. Eighteen F_1 strains obtained from the crossings were used for the estimation of heritability (hN^2) by offspring-parent regression method in two cuttings in 1978 and 1979. As clear differences were observed between the range of digestibility in offsprings and in mid-parents, regressions were calculated after standardizing figures. As the results, high heritabilities hN^2=0.73 and 0.78 for the first growth and 0.70 and 0.84 for the aftermath were estimated in 1978 and 1979 respectively (Fig.4 and Fig.5). Heritabilities for the first growth seem to be over-estimated. Because, the author reported the high interactions between year and digestibility of orchardgrass plants in the first growth. Furthermore, some other researchers reported no selection effect for the digestibility of the first growth. However, the interactions between these two factors were low in the aftermath. The results of these experiments suggest that selection effect for digestibility would be higher in the aftermath than in the first growth.

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Reactions of alfalfa varieties of diverse origin to southern blight (Corticium rolfsii), which is an important disease in warm region of Japan, were tested in the inoculated field of Aichi-ken Agricultural Research Center. Ten varieties and strains were tested twice in space planted conditions in 1972 and in 1973. Seven varieties and strains were common to the first and the second tests. The hypha of southern blight were inoculated repeatedly on the crown of the plants in June and July. Mean percentages of the dead plants by southern blight were 20.6% in the first test and 56.3% in the second test. The dead plants by southern blight were more numerous in 1973 when high temperature continued longer, than in 1972. Cherokee was the highest in the percentage of dead plants by southern blight, followed by du Puits and Europe. The varieties of flemish type seemed more susceptible to the disease than others. The varieties with the lowest dead plant percentage were Moapa and Aikei No.4 throughout the two tests. The varieties adapted to warm region seemed less susceptible to southern blight. The correlation coefficient in percentage of the dead plants between the first and the second test was 0.930, and the varietal difference in analysis of variance for the dead plant percentage was highly significant. It was clearly recognized from these results that alfalfa varieties reacted differently to southern blight, and the difference was mainly caused by genetic variations.

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Based on results reported in the previous paper (INAMI and SUZUKI 1981), breeding of resistant alfalfa to southern blight (Corticium rolfsii), which is an important disease in warm region of Japan, was started from 1973, and selected strains were tested for their resistance in 1978 to prove the effect of selection of survived plants under inoculation. Selected strains named as CRSY group (three strains), were tested with three check varieties at Aichi-ken Agricultural Research Center and Kyushu National Agricultural Experiment Station. Three check varieties were Natsuwakaba which was the main breeding stock, Moapa, the most resistant commercial variety as reported in the previous paper, and AR 50-1, a resistant strain to anthracnose. The tests in Aichi were conducted in spaced planting and sward condition using micro-plots, and the test in Kyushu was conducted in spaced planting condition. Inoculations of southern blight were conducted by the same method as reported in the previous paper at both locations. The correlation coefficients between two locations in spaced planting condition in percentage of infected and dead plants by southern blight were positive and significantly high. All strains of CRSY group were more resistant than Natsuwakaba, and CRSY 521-1 which was selected strongly for resistance to southern blight was the most resistant at both locations. By Duncan's multiple range test using results of two locations combined, CRSY 521-1 and CRSY 523-1 formed the lowest group "a" significantly different from others in percentage of infected plants, and CRSY 521-1 was "a" rank and significantly different from all others in percentage of dead plants (table 5). Strains of CRSY group were resistant under sward condition, too. As the result, it was concluded that the selection for southern blight resistance was clearly effective, and the possibility of breeding varieties resistant to this disease was experimentally proved.

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Oat stem rust was isolated from forage oats at Hamatonbetsu-machi, Hokkaido, Japan in September 16, 1979. Race determination was carried out at National Grassland Research Institute with two race differentiation systems. Result from the system by STEWART & ROBERTS (1970) indicated that the isolate was race 94, which was synonymous with race 6AFH. Result from the another system by MARTENS et al. (1979) indicated that the isolate belonged to a new race which have the avirulence/virulence formula of Pg genes 13, 15, 16, a/1, 2, 3, 4, 8, 9. The race resembled but distinctly differed from some of North American races such as NA 27 (9, 13, 15, 16, a/1, 2, 3, 4, 8) or NA 30 (13, 16, a/1, 2, 3, 4, 8, 9, 15). Among a hundred cultivars supplied from Seed Storage Laboratory, National Institute of Agricultural Sciences, Junegrain was resistant (Table 1). On the other hand, five of twelve commercial cultivars tested, showed considerable resistance. Some wild species from Canadian wild oat gene pool were tested for resistance. Among the tested, CAV 2095 (A. fatua L.) was the only resistant hexaploid line (Table 2).

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In order to assess the changes of various structures in a permanent pasture ecosystem due to cessation of grazing, studies were carried out from 1976 to 1979 in the pasture dominated by orchardgrass, extending on southern slope of Mt. Asama in Nagano prefecture. This report deals with the changes of soil physical conditions of the following three experimental plots ; Control plot: managed by rotational grazing ; Ca-exclosure plot: prohibited grazing from 1976 to 1979, with CaCO_3 (2 ton/ha) application at the beginning of excluding; Exclosure plot: with no CaCO_3 application. The experimental results obtained were as follows: 1. Three phase distribution of 0-15cm soil layer in control plot was almost unchanged throughout 4 years. In both exclosure plots, however, solid and liquid-phase of the soil decreased and gaseous-phase increased, especially evident in the upper soil layer. 2. The soil hardness in control plot increased with the increment of trampling pressure and was always harder than that in both exclosure plots, where the soil hardness decreased markedly in the upper soil layer. 3. The percentage of water-stable soil aggregates larger than 1mm diameter decreased with increment of soil depth in control plot, but in both exclosure plots the percentage reversely increased. 4. These changes of soil physical conditions caused by cessation of grazing were accelerated by applying CaCO_3.

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A series of field experiments was undertaken to assess changes of some structures in a pasture ecosystem due to cessation of grazing This report deals with the changes of earthworm and white grub populations in the following three experimental plots; Control plot: managed by rotational grazing ; Ca-exclosure plot: prohibited grazing from 1976 to 1979, with CaCO_3 (2 ton/ha) application at the beginning of excluding; Exclosure plot: with no CaCO_3 application. The experimental results obtained were as follows: 1. Populations of earthworms, with Allolobophora japonica and Pheretima sp. increased with cessation of grazing, especially Pheretima sp. increased in Ca-exclosure plot. 2. In control plot, earthworms almost concentrated in the top 5cm soil layer, but in both exclosure plots the considerable numbers were found below 5cm layer. 3. In Ca-exclosure plot, the amount of feces deposited on the soil surface by earth-worms from April to October in 1976 reached 1200g/m^2 dry matter, which was about 60 times as much as in control plot. 4. Populations of larvae of Scarabaeidae decreased with cessation of grazing, especially the decrement in the top 5cm soil layer was marked.

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In the previous papers the following results have been reported ; 1) Temperature response of germination and growth is different greatly by subfamilies or tribes and is characteristic of subfamilies or tribes in the grass family, 2) Species of Festucoideae are the cool type in temperature response and may be adapted to cool regions, while those of Panicoideae and Eragrostoideae are the warm type and may be adapted to warm regions. On the other hand Oryzoideae and Arundinoideae include the heterogeneous tribes in temperature response, and some species of Ehrharteae and Danthonieae are the cool type, while some others are the warm type. In the present paper, the distribution of subfamilies and tribes in relation to climatic factors was dealt with in order to make sure the relationships between the pattern of temperature response and distribution of subfamilies and tribes. Both horizontal and vertical distributions were studied by literature survey in Japan and its environs, in the tundra region of Canada, Alaska and USSR, in the mountains of India, Nepal, Kenya, Tanganyika and Guatemala. The following results were obtained ; 1. In the low altitudes (less than about 2300m) of tropics the warm type grasses belonging to Eragrostoideae, Panicoideae, certain tribes of Oryzoideae and Arundinoideae occurred. Few of the cool type grasses belonging to Festucoideae, Ehrharteae and Danthonieae were distributed in this region. 2. In the high altitudes (more than 2300m) of tropics and the subarctic region the cool type grasses occurred, while none of the warm type grasses were distributed except several species of Andropogon (the panicoid grass) in Tanganyika and of Muhlenbergia (the eragrostoid grass) in Guatemala. 3. In the region of middle latitudes both of the warm type and the cool type grasses occurred. 4. From these results, the uniformity of temperature responses and distribution of subfamilies or tribes were discussed.

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This study was carried out to determine whether or not the reduction of seed yield due to the high level of nitrogen results only from the effect of lodging. The levels of nitrogen studied were 0 (0N), 1 (IN, ) 2 (2N) and 4kg N/a (4N) and the latter two levels were taken for high levels of nitrogen here. In relation to the lodging, treatments consisted of 1) the lodged plot in which the plant was left lodging naturally by rain, wind etc. and 2) the prevented plot in which the plant was supported mechanically by means of bamboo frames. In both lodged and prevented plots, nitrogen application increased the forage weight, but the difference among levels of nitrogen was not found in the prevented plots whereas a marked difference in the lodged plots, showing an increase in forage weight with more nitrogen. The lodging in plots without nitrogen was less and occurred later than in plots with nitrogen, and among those it was less and not severe in plots 1N compared with those having higher levels of nitrogen application. Higher number of ears was produced in the prevented plot than in the lodged one. But the change of number of ears due to the level of nitrogen differed between Waseaoba and Yamaaoba and between lodged and prevented plots, that is, in Yamaaoba the maximum number of ears came out by 1N in both lodged and prevented plots, but in Waseaoba it came out by 1N in the lodged plot and by 2N in the prevented plot. Consequently, the difference in number of ears between varieties become greater in high levels of nitrogen. Higher seed weight per ear was also produced in the prevented plot than in the lodged one in all levels of nitrogen in both varieties, but the difference was observed between varieties in response to the nitrogen application. Seed yield was remarkably higher in the prevented plot than in the lodged one irrespective of varieties and levels of nitrogen. The effect of prevention of lodging was greater in high levels of nitrogen. The decrease of seed yield in the lodged plot was greater with more nitrogen, but the seed yield in prevented plot was also significantly decreased due to high levels of nitrogen as in lodged one. Consequently, it was recognized that the decrease in seed yield due to high levels of nitrogen application resulted not only from the lodging but also from other physiological reactions in plants.

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Pot experiments were conducted to find out the best condition of fertilizing for the improvement of establishments of several warm-season grasses oversown into Italian ryegrass (Lolium multiflorum, abbr. as Ir) swards. And specific differences among warm-serson grasses were studied from the aspect of their early growth rate and roots development and nutrients absorption during their establishing on non-tilled Ir sward. 1. Several warm-season grasses; Rhodes grass (Chlolis gayana, abbr. as Ro), Sweet sorghum (Sorghum vulgare, abbr. as So), African millet (Eleucine corocana, abbr. as Am), Green panic (Panicum maximum, abbr. as Gp), Coloured Guneagrass (Panicum coloratum, abbr. as Cg) and Fingergrass (Digitaria adscendens, abbr. as Fg) were grown in the green house under the given conditions. The mineral concentrations of each grasses were investigated every fifth day after their germination. Nitrogen concentration of each grass were lower in the non-plowed plot than in the plowed one. The lower N concentration of each grass was supposed to be caused by the competiting nitrogen absorption from soils between preceding and succeeding grasses. Large parts of fertilized ^<15>N were apparently incorporated into preceding grass (Ir). And relative value of ^<15>N incorporation into each warm-season grasses grown under the non-plowed plot against that of the plowd plot was ranked as Am> So≫Ro. 2. The effect of nitrogenous fertilizer application rates on the germination, the early growth rate and establishment of Am, So and Ro oversown into Ir swards was investigated. The weight of dry matter of earch warm-season grasses increased with increasing nitrogen during their early growth stages, that's adequate nitrogen application decreased the competition between preceding and succeeding grasses for N. Heavier nitrogen fertilization, however, caused the suppression of the germination of warm-season grasses. And it was found that the such inhibition of their germination with heavier nitrogen application was caused by higher salinity of the surface soil. 3. The germination and establishment rates of Am and So were higher than that of Ro. Warm-season grasses having the larger R/T ratio (the ratio of root length to plant hight and root weight to plant weight), the higher establishment rate would be obtained. And this fact shows that the initial development of the root might be very important for their establishments on non-tilled Ir sward.

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The objective of this study was to determine the optimum harvesting stage of corn for the whole crop silage. The changes of the fermentative quality, nutritive value, nutritive yield of the crop as silage with regard to stage of maturity, and the amount of voluntary intake by the cow were investigated in 1975 and 1978 in Hokkaido prefecture. Varieties used were HEIGENWASE (1975) and WASEHOMARE (1978). The whole crop corn silages were prepared at four different stages, i.e., milk, dough, dent and over-ripening stages. The results are summarized as follows: 1. The rations of the grain component to the total dry weight increased gradually as the stage of maturity advanced from milk to over-ripening stage and they were 48.3% for HEIGENWASE and 46.2% for WASEHOMARE in the late dent stage, respectively. 2. The moisture contents in WASEHOMARE decreased linearly from dough stage (79.4%) to over-ripening stage (62.5%), and HEIGENWASE showed the similar tendency. The starch contents increased with the advancing stage of maturity, and they were 28.6% for WASEHOMARE, and 28.4% for HEIGENWASE in the late dent stage, respectively. The crude protein contents at early harvest times were higher than those at late harvest times, difference being from 2.7% to 4.3%. 3. Acidity in the silage rose gradually with the advancing stage of maturity from 3.6 or 3.7 to 4.1, and it was 3.8 in the late dent stage. The values of chemical score on silages at the late dent stage markedly exceeded those at other stage. 4. Total digestible nutrients (TDN) contents in milk, early dent, late dent and over-ripening stages were recorded ; for HEIGENWASE ; 70.4, 73.6, and 70.8%, and for WASEHOMARE ; 70.8 (dough), 68.1 (dent), 69.1 (late) and 65.4% (over-ripening), respectively. The digestible crude protein contents in HEIGENWASE decreased with the advancing stage of maturity, but in WASEHOMARE, they decreased only after the overripening stage. 5. The voluntary intake by the cow at the milk stage was 8.39kg, 11.3kg at the early dent stage, 12.3kg at the late dent stage, and 11.3kg at the over-ripening stage, respectively, and it was greater at the late dent stage than at any other stages. 6. The yield of TDN per are was greater at the late dent stage than at any of the milk, early dent and over-ripening stages. 7. From the results described above, we may conclude that, in the preparation of silage with whole crop corn, it is advisable to harvest the crop at the late dent stage.

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The experiments were undertaken to investigate the influences of frost injuries on the fermentative quality, nutritive value and harvest loss of corn silages. The varieties used were KO No.8, HOKUYU and PIONEER No.3715. The silages were prepared at three different stages, ranging from milk to over-ripening stages, and their nutritive value, feed composition, and chemical quality were determined. The corn plant were decolorized on upper one third part of plant by the mild frosts for two or three times, and the much frequent heavier frosts brought about decolorization of whole plant. The contents of moisture, crude protein and monosaccharides of corn silages decreased with the frost injury. The total acids in silages decreased with the frost injury. Consequently, the pH of silage rose from 3.7 or 3.9 to 4.5 or 5.3. The digestibility of crude protein decreased gradually due to the frost injury, but the dry matter digestibility, digestible organic matter and TDN contents of silages were not very much changed. The harvest loss in fields increased due to the heavy frost injury. It is advisable to harvest the crop before it undergoes more than two or three times of frosts, if better quality silage is desired.

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Farms breeding beef cattle highly depend upon lands, because the use of roughage is indispensable there. Therefore, we set up in this article the subjects to clarify: (1) a rationally organized system of feed production corresponding to changes of the farm scale in land area, and ; (2) a highly profitable system of land use in beef-cattle breeding farms with standard land area. The methods of study in the first subject are as follows: with respect to the system of breeding beefcalves (fattening cattle) and the use of roughage, 12 variants of production processes (of grass and corn silage) are set up ; for each variant respectively, labour forces are defined to 2 of family labour forces (basic labour forces) and land areas to 6 different scales of 30, 40, 60, 80, 100 and 120 ha, and ; linear programming models are constructed to approach solutions. In the second subject, we suppose specialized farms for breeding based upon 3 typical systems of land use, having a standard scale of land area of 30ha, and tried to find optimum solutions for each type of land use. The results of the operation show: in the first subject, with respect to the specialized farms for beef cattle breeding, having 2 family-labour-forces, an intensive land use in appropriate for farms with smaller scale of land area, while an extensive land use is favourable for those with larger scale of land area, and ; in the second subject which assumes the farms with the same scale of land area, the beef cattle breeding farms based on an intensive land use system are more advantageous in view of profitability.

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Pure swards of perennial ryegrass (Petra) and orchardgrass (Kitamidori) were harvested at the stages of maturity during first growth in the spring and at the subsequent three-weekly regrowths. Each batch of herbage was fed to 5 wethers ad libitum and a digestion trial was conducted. In comparison with the orchardgrass, contents of cell walls, acid detergent fiber, acid detergent lignin, ether extract and gross energy of perennial ryegrass were low, and conversely cell contents and its digestibility were high. Voluntary intake, digestible energy contents, digestible energy intake and nutritive value index of perennial ryegrass grown in spring and autumn were higher than those of orchardgrass, but those of aftermath in summer were lower than those of orchardgrass. There was significant correlation between the temperature (x: ℃) in the preceding each cut and dry matter digestibility (y: %), and the following equation was observed. perennial ryegrass: y=95.5-1.49x(r=-0.87, p<0.01) orchardgrass: y=73.9-0.54x (r=-0.60, p<0.05)

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