In order to clarify the inheritance of northern anthracnose (Kabatiella caulivora) (Kirchn.) Karak.) resistance in red clover, the expriments were carried out through 1973 to 1976. Two resistant parental plants from two cultivars (R-1, R-2) and two susceptible parental plants (S-1, S-3) from two cultivars were crossed. Seven resistant F_1's of resistant plant×resistant plant were inter-crossed each other, and 12 F_2's were obtained. Seven resistant F_1's of resistant plant×resistant plant were also test-crossed with susceptible plant, S-1. The spore suspension (10^6/ml.) of race "K-1" were inoculated under the condition of 19-22℃ and 100% of humidity for 48 hours. After the inoculation, the plants were water-sprayed 4 to 5 times a day in order to keep high humidity. Susceptibility was checked on the 14th day after inoculation. Artificial inoculation was repeated three times, and when discrepancies occurred between the three ratings in the three inoculation on a plant, the plant was assigned to the higher rating basis of susceptibilities are as follows; Resistant: no visible symptoms or minute black flecks on the stem or the petiole. Susceptible: longitudinal grayish brown spots in the stem or the petiole. The following results are obtained: 1. F_1 plants of resistant parental plant×resistant parental plant segregated in a ratio of 9 resistant to 7 susceptible. F_1 plants of resistant parental plant×susceptible parental plant segregated in a ratio of 1 resistant to 3 susceptible. F_1 plants of susceptible parental plant×susceptible parental plant were all susceptible. 2. In the crosses of resistant F_1 plants of resistant parental plant×resistant parental plant with the susceptible plant, S-1, the immediate progenies segregated in a ratio of 1 resistant to 3 susceptible or in a ratio of 1 resistant to 1 susceptible. 3. Six F_2's out of 12 inter-crosses of the 7 resistant F_1 plants segregated in a ratio of 3 resistant to 1 susceptible. The other six F_2's were all resistant. From the above results, the resistance to Kabatiella caulivora (Kirchn.) Karak. was controlled by two dominant complementary genes.

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The authors compared the effects of light on the mitatic activities and cell elongation in seminal roots of Zea mays with samples treated two days after- and four days after seeding. Seeds were germinated on wet filter paper in germination box under the temperature of 25-28℃. Fluorescent lamp was used at six watts for lightening and twelve hours intermittent light treatment. The results are summarized as follows: 1) Vigorous mitotic activities wereobserved with light- and intermittent light treatment which disappeared at around 1100μm from cap initials. Cell divisions were less frequent under darkness and the site of maximum activities was 100-200μm backwards as compared with other treatments. Some mitotic activities were observed even in the elongation zone. 2) Cell length in root tips were measured of epidermis, cortex and stele at each 100μm sections. Cell length increased more under dark conditions at elongation zone. 3) Growtn of seminal roots and plumules were measured for seven days after seeding. Light did not give any direct effect on the growth of seminal roots and the barkness did much to the elongation of mesocoty. From above results, it is suggested that some environmental factors such as light may influence the pattern of root growth that has been considered to be controlled by endogenous factors.

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A grasp of the metachronal succession of growth of forage crops is important in order to decide when they should be clipped. One drawback in the method now widely used to analyze growth patterns is the fact that the growth function used to draw the growth curve can only be obtained by connecting discontinuous straight lines. In addition, the observed values are fluctuated by various incidental factors. A grasp of the metachronal succession of growth becomes possible if the observed values can be fitted to a regressive curve by statistical treatment. In the present research, Italian ryegrass was studied to see whether logistic curves could be made to fit autumn, winter and spring growth. The logistic equations for the increase of top dry matter was in all cases significant at the 0.1% level. Regressive curves could thus be obtained which accurately reflect the growth process. In the two cases out of a total of nine, the logistic equations for increase in the leaf area index did not permit regressive treatment due to slight damage from wind and lack of water subsequent to the period showing the optimum leaf area index. In the other 7 cases, however, the regressive coefficients were at the 0.1% level, and significant logistic regressive curves could be obtained. The gradient of each logistic curves which could be compared by the parameter k of the logistic equations, differented in each experimental years and seasons. The more gently gradient of the increasing curves of top dry matter and leaf area index were shown in order spring, autumn and winter growth. In addition, the regressive coefficients for the relations between integrated air temperature or integrated solar radiation and increase of top dry matter were at the 1〜0.1% level. Significant logistic regressive curves could thus be obtained. The gradient of the increasing curves of top dry matter which depending on the integrated air temperature or the integrated solar radiation, become steep under the condition of the lower temperature, and the stronger solar radiation.

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The Japanese barnyard millet plants having been grown for 10 days under 3 temperature regimes (day/night, 30/25, 24/19 and 17/12℃) with natural light were cut at 5 cm height above ground and transfered each to the above 3 temperature rooms to compare the regrowth process. 1. Temperature before cutting and growth: Plant height, tiller number, leaf-number, leaf area and dry weight, and RGR, RLGR, NAR at the cutting date when the pre-treatment finished, all increased with increased temperature. 2. Temperature after cutting and regrowth: (1) Tillering rate and regrowth were greatest on the plants having been grown at 17/12℃ before cutting, while the regrowth increased with increased temperature after cutting. (2) Nitrogen and TAC concentrations of the stubble at the 20th day after cutting were greater on the plants grown at lower temperatures before cutting and also at lower temperatures during regrowth. (3) Plants with a higher nitrogen or TAC concentration of the stubble at the cutting date made a greater regrowth, although their contents had no correlation with the regrowth. 3. In the regime of this experiment, the regrowth of Japanese barnyard millet after cutting increased with decreased or increased temperature before or after cutting, respectively.

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Studies were undertaken to investigate the physiological mode of species difference in resistance to summer depression of temperate grass. Tall fescue and perennial ryegrass which were resistant and susceptible to summer depression, respectively, were grown in 1/5, 000 are Wagner's pots, and were treated by high soil temperature. Species difference in growth inhibition by high soil temperature was hardly observed in the experiments carried out in December and April, whereas in the experiment carried out in August lesser extent of growth inhibition by high soil temperature was observed in tall fescue as compared with perennial ryegrass. In the experiment carried out in December, no changes in leaf water content due to high soil temperature were observed in both species. However, in the experiment carried out in April decreased leaf water content of perennial ryegrass affected by high soil temperature was observed in midday of fine weather, whereas no decreased leaf water content due to high soil temperature was observed in tall fescue. In both species, high soil temperature hardly seemed to affect the stomatal opening. On the other hand, greater extent of traspiration inhibition by high soil temperature was observed in perennial ryegrass as compared with tall fescue. It may be concluded that one of the reason, by which the susceptibility of pernnial ryegrass to summer depression is explainable, is the water imbalance caused by both high soil and air temperatures which inhibit water absorption and stimulate transpiration, respectively.

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In southwestern area of Japan, association of temperate and tropical grasses is necessary to prolong grazing period and to reduce the seasonal fluctuation of yield in pasture. In this experiment tall fescue-dallisgrass pasture was grow at two levels of nitrogen fertilization. The yearly yield of herbage and seasonal herbage production of mixed pasture and each grass were investigated. The results obtained were as follows: 1) In yearly yield of herbage, mixed tall fescue-dallisgrass pasture was higher than tall fescue or dellisgrass pasture. 2) The herbage production of mixed pasture had two peaks in June and in September, but the seasonal fluctuation of its herbage production was smaller than that of combined pasture (utilizing tall fescue pasture with dallisgrass pasture, in 1 st report of this title). Two peaks of herbage production in mixed pasture were much the same height (in combined pasture, the peak in June was higher than that in September). The herbage production in early spring was higher in the mixed pasture than in the combined pasture. 3) In the mixed pasture, the herbage production from March to June was mainly composed of tall fescue, that in July was composed of tall fescue and dallisgrass, and that from August to September was mainly composed of dallisgrass. 4) In seasonal herbage production, each grass in mixed pasture was different from each pure pasture. From March to June, tall fescue in mixed pasture was much the same yield as that in pure tall fescue pasture, but from July to September, the former was lower than the latter. From April to June, yield of dallisgrass in mixed pasture was lower than that of pure dallisgrass, but from July to September both were approximately the same. Competition between tall fescue and dallisgrass in mixed pasture is illustrated in Fig. 4.

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An experiment was conducted to investigate the response of warm-season grasses to the different duration of light competitive condition with preceding cool-season grasses into which the former species were undersown. Four warm-season grasses, i.e. green panic (Panicum maximum var. trichoglume cv. Petrie, abbr. as P), setaria (Setaria anceps cv. Kazungula, abbr. as S), rhodesgrass (Chloris gayana cv. Pioneer, abbr. as R), and dallisgrass (Paspalum dilatatum, abbr. as D), were sown in 12 cm diameter pots with four replications on Sep. 1, 1975. It consisted of five treatments regarding number of days under shade (29% daylight, abbr. as shade or s), i.e. 0s, 12s, 21s, 27s, and 34s from sowing, and then moved into light (87% daylight, abbr. as light), shown in Fig. 1. 1) Total plant dry weight showed the highest in R under continuous light (0s), but under continuous shade (34s) P was the highest, and S, R, and D decreased in order (Table 1). 2) The reduction of RGR owing to the shading was heavier in D, comparing other species. Two modes of adaptation to compensate the lowering of RGR under shade were observed, i.e., by means of a) the increased LAR in accordance with the higher SLA such as P, or the higher value of SLA and LWR such as D, and b) the least decline of NAR such as S and R (Table 2 and 4). 3) The increase of RGR after the transference from shade into light was observed in all the species. But after 27 days of shading, P showed less recovery comparing to D (Table 3). 4) The relationships between the log value of the total relative radiation (ΣR) and RGR were as follows (Fig. 2), a) In sptite of the highest RGR under light, R decreased rapidly in accordance with the shading. b) The smallest RGR was observed under both light and shade in D. c) The reduction of RGR with that of ΣR was not severe in P and S, comparing to R and D. 5) The difference in the shape of leaf blade among those developed under shade and light was observed especially in D (Table 5). 6) These results show that P, S and R may be suitable for undersowing practice in respect of higher dry matter production up to about 20 days of 30% daylight. But D is characterized in the highest recovery of RGR after transference into light.

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In this paper, the authors, in order to comprehend the outline on the detachment of rooted nodes which has an important role in the propagation of Kudzu vines, investigated (1) The number of root systems per plant and the developmental stage of these root systems (The root system is generally composed of several roots that differ in their function and form), (2) The total length of the connecting stem per plant (The stem between stubble and rooted node, or between one rooted node and another in a plant, were designated as the connecting stem.), (3) The internode composition of the total connecting stem of the plant with the number of vascular bundle rings and its composition ratio (The connecting stem is generally composed of internodes that differ in their number of bascular bundle rings). We were led to the following conclusions: In most cases, a rooted node is detached independently or a few of the rooted nodes in a line are detached from the stubble. Moreover, most rooted nodes are detached before their root systems grow to R-IV. The internodes of the connecting stem are generally dead or are cut off before the third vascular bundle ring is formed. These facts suggest that the detachment of rooted nodes is fairly frequent. The death and the cutting of connecting stems are caused by injury from insects and diseases, or from physiological deterioration of the internodes.

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In order to evaluate the digestion. in the rumen of herbage. tissues with special reference to the ceil wall, orchardgrass leaf blades were treated with pectinase and divided into three tissue fractions ; the parenchyma fraction consisting of photosynthetic parenchyma cells, the mechanical tissue fraction consisting of sclerenchyma, vascular bundle and epidermis, and the mixed tissue fraction. Recovery percentages of neutral detergent fiber (NDF) of the leaf blades in the parenchyma, mixed tissue and mechanical tissue fraction were 19, 11 and 59, respectively. The lignin content was higher in the mechanical tissue fraction than the parenchyma fraction. NDF digestibility in vitro was 96% for the parenchyma fraction and 69% for the mechanical tissue fraction, and that of the original leaf blades was an intermediate (84%) of the two fractions. These results suggest that the extent of digestion of herbages is dependent on the quantity and the digestibility of NDF in the mechanical tissue fraction, and is independent of the quanitity of the parenchyma fraction.

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One of the phenolics bound to the fibrous fraction in the stubble of orchardgrass (Dactylis glomerata L.) was shown to be chlorogenic acid by paper chromatography and ultraviolet absorption spectrometry.

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In the previous paper, we described that the nitrate accumulation related closely with the age of fodder turnip. The purpose of the present report was to examine the differences in nitrate accumulation among species or varieties of forage crops. For this reseach, culturing conditions were investigated by using Italian ryegrass as a test plant. And then, forage crops of 21 species and 44 varieties were grown with the same nutrient solution contained 100 ppm of nitrogen. The results obtained were as follows. 1. The contents of nitrate nitrogen in Italian ryegrass increased with the increasing of concentration of nitrate nitrogen in the culture solution. Especially, its contents increased almost linearly at any varieties, as the concentration of nitrate nitrogen in the medium was increased up to 100 ppm. 2. The contents of nitrate nitrogen in both the top and the root of Italian ryegrass were markedly high in the early stage of growth and decreased gradually with aging. 3. Growing in the nutrient solution contained 100 ppm of nitrate nitrogen, some differences of nitrate accumulation in plant among species or varieties was observed. The level of nitrate accumulation of each species decreased in following, order on the basis of their mean values. Grasses: orchard grass (17.71mg as nitrate nitrogen per 1 gram in dry matter)> timothy (16.99)>medow fescue (16.19)>kentucky blue grass (14.97)>rodesgrass (10.13)>Italian ryegrass (10.23)>bent grass (9.20) Legumes: white clover (17.27)>alsike clover (15.71)>red clover (13.81)>alfalfa (7.75)On the other hand, the varitation of nitrate contents in Italian ryegrass was markedly larger than those of orchard grass or timothy. 4. The contents of nitrate nitrogen in alfalfa at any time of repeated harvests were usually lower than those of Italian ryegrass, red clover and white clover. 5. The nitrate accumulation in leguminous forages were higher than might be expected. For example, 17.46mg as nitrate nitrogen per 1 gram in dry matter was observed in white clover.

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The purpose of this study is to investigate the influence of heifers sociability on their liveweight gains in Holstein breed being grazed on public pasture. 81 raising Holstein heifers were used for this investigation, at Itayama pasture Shibata-shi in Niigata prefecture from May to October in 1973. The agonistic behaviour in the herd was observed and the relationships between the liveweight gains during the grazing season and the social order and the number of cows fed in the owners' barn were examined. The results are summarized as follows: 1. A significant positive correlation (r=0.503^<**>, r=0.423^<***>) was recognized between percentage of victories and age in month in early and later term of grazing. 2. A significant positive correlation (r=0.466^<***>) was recognized between percentage of victories and bodyweight in later term of grazing only. 3. The percentage of victories and the ranking of the heifers which have experienced grazing in the preceding year were higher than the newly grazed heifers. 4. The percentage of victories and the ranking of the heifers introduced later were lower than the other heifers introduced earlier. 5. A significant positive correlation (r=0.670^<***>) was recognized between liveweight gains during the first month after grazing and the gains throughout the grazing season. 6. As the number of cows and heifers fed in owners' barn before grazing increased, the liveweight gains of these heifers showed a tendency to increase after grazing implying that the liveweight gains could be promoted when heifers, having been fed in fewer herd in owners' barn, would be fed outside of the barn in small groups for a certain period before grazing to pasture.

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In order to analyze aspects of the cohesive tendency in cattle, the behaviours of grazing cattle were investigated for 20 days from June to August. The investigations were done in a herd composed of 12 Japanese Shorthorn heifers, 6 Japanese Black steers, 6 Holstein steers and one Japanese Shorthorn bull grazed on a native grassland of about 90 ha at Kawatabi Farm of Tohoku University. As some subgroups were formed in a herd while grazing, the composition of each subgroup and the location and body axis of all cattle were recorded at 10 minutes intervals in order to analyze the distribution and character of each cattle in a herd. Results are summarized as follows: 1) Holstein cattle showed the most marked breed integration. Japanese Black cattle had the strong tendency to from the subgroups within breeds rather than between breeds. Japanese Shorthorn cattle exhibited weak own-breed integration and preferred the Japanese Black breed. 2) In the subgroups while grazing, the differences in the locations and body axis of cattle among breeds were significant. Japanese Shorthorn cattle exhibited the weak tendency to follow neighbours rather than the other breeds did. Holstein cattle hardly differ from neighbours in behaviour, while Japanese Black cattle were not always at the heads of moving columns. 3) Some individuals with weaker cohesive tendency were frequently at the heads of moving columns or moved away from their neighbours while grazing. 4) A hull mostly move away from their neighbours and didn't show the grazing behaviour while the other cattle exhibited grazing behaviours. 5) The grazing formations which had only one direction of the grazing movement and contained some individuals that were at the front of a moving column, so to speak the pear-shaped grazing formations, were 47% of total grazing formations, so it was considered that this grazing formations were typical. 6) The grazing formations which had several directions of the grazing movement were 33% of total grazing formations. Therefore, it was clear that a herd always had a sign of separation of subgroup while grazing.

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In order to investigate the influences of seasons and the paddock size on the spatial pattern of grazing cattle, the distributions of grazing cattle on the mixed pastures were constructed on the maps of each paddock at 5 minutes intervals. The distances to the nearest neighbors were measured for each cattle and the method of Clark and Evans (1954) was used to test the difference and randomness of locations. Observations were made up with four Japanese Shorthorn steers in 1974 and four Japanese Black steers in 1975. These herds were pastured on eight paddocks of from 6.25a (25×25m) to 75a (50×150m) area during observation periods of each season. The results observed were as follws: 1) The influence of seasons In summer, grazing cattle were the most strongly aggregated of the three seasons. In autumn, cattle grazed dispersedly. In spring, grazing cattle showed the midway spatial pattern between those in summer and in autumn. 2) The influence of the paddock size In spring and autumn the larger the paddock size was, the lower the R-values, the measure of the degree to which the observed distribution departed from random expectation, were made or the more cattle grazed aggregatively. And the smaller the paddock size was, the higher the R-values were made or the more cattle grazed dispersedly. The R-values showed the one peak on the paddocks of from 35a (50×70m) to 40a (50×80m) area.

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