SHIYOMI et al. observed theoretically and experimentally in 1983 that the frequency distribution of herbage mass per unit area in grazing pastures was well described by a gamma distribution. They developed later a useful method to estimate the mean and degree of spatial heterogeneity of herbage biomass over the pasture area using the gamma distribution. In 1995, Liu and HIRATA stated in their paper that the goodness of fit test using X^2-statistics showed that the gamma distribution was not applicable to the observed frequency distribution of bio-mass of a Pensacola bahiagrass pasture. In the current paper, we state that (1) the gamma distribution was statistically valid for application to the bahiagrass data, too, and (2) a good estimate of the distribution mean could be obtained by a labor- and time-saving method if a gamma distribution is assumed as a frequency distribution of bahiagrass biomass.

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Variation in reproductive allocation pattern was studied about 13 populations of Poa annua L. from two golf courses. Based on variations in plant biomass, reproductive traits and the relationships among those traits, four groups were recognized: (A) Plants matured quickly and produced small plant biomass resulting in the highest RA. Seed weight per plant was dependent on plant biomass, but independent of RA. (B) Plants produced small plant biomass, but they headed late. They were medium to high in RA. Their seed weight per plant was dependent on plant biomass and RA. (C) RA was medium. Plants matured quite early. Their seed weight per plant was dependent on plant biomass and RA. (D) Plants headed latest and exhibited the lowest RA from large plant bio-mass. Seed weight per plant was independent of plant biomass. In the Group D, the earlier plants headed, the more seeds were produced. Plants in green were included in Group A or B, and produced small plant biomass resulting in high RA. Contrarily, fairway and rough plants belonged to Group C or D, producing large plant biomass from heavy seeds (low RA). Tee ground consisted of three Groups, A, C and D diifering in plant size and reproductive traits. The high seed fecundity of green plants appeared to be necessary to survive in green Large plant biomass which was produced from heavy seeds of fairway and rough plants seemed to be favorable under competitive conditions.

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In a Trifolium repens-Zoysia japonica sward, new members of T. repens recruit frequently via seed reproduction into the adult population. In this paper, we assessed the amounts and patterns of genetic variations in architectural and clonal growth traits within the seed population of T. repens to understand how much variations are potentially supplied via seed reproduction to the adult population. Inter-relationships between these traits, especially those between stolon attributes were also examined. Thirty-six clones derived from the seeds were assessed for these traits using a common garden technique. The results clearly showed that large intra-population variations existed in almost all the traits examined and large differences existed in quality as well as quantity of stolon bank among the clones. Estimation of biomass distributional pattern in stolons according to branching order indicated the presence of a wide variation ranging from lower-ordered clones to higer-ordered ones. Analysis of the relationships between stolon attributes suggested that there would be trade-offs between stolon diameter and either stolon length or number. Eco-logical significances of these variations in clonal growth traits were discussed in relation to a patchy property of the sward population coexisting with Z. japonica.

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To clalify the benefits of using lime-coated alfalfa seeds, the establishment and yield were surveyed for three years under broadcasting and row seeding conditions, compared with the vacuum-processed seeds. No beneficial effects of the coated seeds were observed on the growth of seedlings one month after sowing. However, the survival rate of plants was about 10% higher for coated seeds than vacuum-processed seeds after the second harvest in the seeding year. The plants grown from coated seeds were heavier than that from vacuum processed seeds up to the first harvest of the second year, when copmpared with plants grown at the same plant density. In case of broadcasting, yield was apploximately 30% higher when using coated seeds than using vacuum-processed seeds for two years after seeding. In case of row seeding, however, the increase in yield attributed to coated seeds occured only in the seeding year. The seeding rates of lime-coated seeds can be saved to 45-60% of the vacuum-processed seeds, through the effects of early nodule formation.

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Alfalfa leaf extracts were prepared by disintegrating fresh herbage, coagulating the green juice by steam injection and separating the curd from the deproteinized juice. Addition of ethoxyquin (w/v) into the green juice at 0.01%, 0.02%, 0.05%, 0.10% and 0.20% levels prior to coagulation gave final concentrations of 0.11%, 0.26%, 0.70%, 1.15% and 2.57% in the freeze dried leaf extract, respectively. Samples, packed in vinyl bags and wrapped in aluminum foils, were stored for 40 weeks at 28℃, 5℃ or -18℃. The lower the storage temperature, the lesser the reduction in carotenoid content was. The rate of loss of β-carotene was much faster than xanthophylls. At high temperature (28℃), ethoxyquin was essential to reduce the loss of carotenoids. Without it, recoveries of β-carotene and xanthphyll in leaf extract were reduced to 3 and 15%, respectively, of the initial values within 40 weeks, but were improved to 30 and 50% by the addition of only 0.01% ethoxyquin. Further addition improved the recoveries a little further to 50 and 60%, respectively, at the highest application level. At low temperatures (5 and -18℃), carotenoids were well preserved without ethoxyquin excepting β-carotene at 5℃. The recovery of β-carotene at 5℃ was only 40% but was improved gradually to 90% with the increase of ethoxyquin levels. The decline of ethoxyquin in leaf extract at temperature above freezing implies that ethoxyquin itself be subjected to degradation. Only slight difference was ob-served between 5℃ and 28℃ in the ethoxyquin degradation.

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Internodes of sorghum and maize plants were micro-surgically dissected into fractions of epidermis (EPI), sclerenchyma (SCL), vascular bundle (VB) and pith parenchyma (PITH) to examine the lignin distribution. The second lowest internode of both plants dissected at the heading and milk-ripe growth stages had the highest lignin concentration in the EPI and SCL followed by the VB, and the PITH had the least lignin concentration. Although lignin concentration increased with maturity of the plants in the EPI and SCL, little changes were ob-served in the lignin distribution. Most of the lignin (84-90%) was found in the rind of the internodes. Lignin concentration in each fraction in the stem inter-nodes of sorghum at the dough-ripe growth stage was EPI=SCL>VB>PITH for the lowest to the 7th internodes, EPI=SCL=VB>PITH for the 9th and 11th internodes and EPI=SCL=VB=PITH for the 13th internode. From the bottom toward the top of the stem, lignin concentration increased in the PITH but it decreased in the EPI and SCL. The lignin concentration in the VB was relatively consistent among the internodes. The proportion of lignin for SCL to the total lignin content was greatest in the lower internodes. The higher the internode the greater the proportion of lignin content in the PITH.

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The effect of urea or ammonia treatment of rice straw on the voluntary intake, digestibility of feed components, energy partition and nitrogen (N) retention of sheep were compared. The pH and ammonia-N concentration of rumen fluid and blood packed cell volume (PCV) were also investigated. The digestibilities of acid detergent fiber (ADF) and neutral detergent fiber (NDF) increased by the treatments (P<0.05). The dry matter (DM), organic matter (OM), crude protein (CP) and energy digestibilities of the urea treated (US) and ammonia treated straw (AS) were also increased by the treatments (P < 0.05). The OM digestibility of untreated straw (NS) was 56.9% and it was increased by 17% and 22% by urea and ammonia treatments, respectively. The CP digestibility was improved more by urea treatment than ammonia treatment. Reflecting the improved digestibility of chemical components of US and AS, the digestible organic matter (DOM), digestible crude protein (DCP) and digestible energy (DE) values were also increased by the urea and ammonia treatments (P<0.05). The intakes of DE and metabolizable energy (ME) were tended to be higher in sheep fed AS than the others. Furthermore, the DE and ME values of straw were also improved by both urea and ammonia treatments. The DM and OM intakes were not increased by urea treatment, however, an increase of 47% was observed in ammonia treatment. The DOM intakes of NS, US and AS were 13.8, 15.8 and 24.9g/kgW^<0.75>, respectively. The N-retention was higher in sheep given the US and AS, however, the significant difference to NS was ob-served for only the AS. The rumen fluid pH was not affected by the urea and ammonia treatments. The rumen ammonia-N concentration was higher in sheep fed US both before and 4 h after feeding. The PCV of sheep was not affected by the urea and ammonia treatments. It can be concluded that ammonia treatment was more effective for the improvement of feed intake. Moreover, urea treatment was found to be as effective as ammonia treatment for improving the digestibility of feed components, nutritive value and N-retention.

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Five cultivars and 12 indigenous wild populations of orchardgrass from the former USSR were evaluated for freezing tolerance, resistance to snow mold caused by Typhula ishikariensis, and other traits related to winter hardiness under field conditions in Sapporo. Three cultivars from Hokkaido (Hokuto, Okamidori, and Wasemidori) were included for comparison. In general, accessions from the former USSR were more tolerant to freezing and snow mold than those from Hokkaido. However, winter hardiness, as measured by the vigor of the plant just after snow melt, was better in cultivars from Hokkaido than in most accessions from the former USSR. Winter hardiness was positively associated with earliness in heading and tolerance to stem rust caused by Puccinia graminis in the preceding year, and negatively associated with winter dormancy (expressed as vigor of regrowth in November). Dedinovskaja 4 was, however, an exception as it was most winter hardy genotype despite long dormancy and delayed heading. Gruzinskaja from Georgia was more resistant to stem rust and grew more vigorously in late autumn than the cultivars from Hokkaido. Two extra early maturing accessions (No. 38091 from Tajikistan, and Leningradskaja from Lenin-grad) showed high tolerance to both freezing and snow mold.

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Naturalized white clover (Trifolium repens) is now widely distributed throughout Japan, from Hokkaido to Okinawa Prefecture in latitude and from almost Om to more than 1,000m in altitude. The objective of this paper is to describe the latitudinal variation in cyanogenesis in Japan and the altitudinal variation in cyanogenesis at Mt. Fuji. Cyanogenesis was examined with a sodium picrate test for 14 natural populations with different latitudes and 4 natural populations with different altitudes along the road at Mt. Fuji. The results confirmed a latitudinal variation in AcLi (the phenotype releasing HCN) frequency with the similar pattern to that well known in Europe ; the northern populations such as those from Hokkaido and Tohoku District showed lower frequencies of AcLi than the southern populations. Further analysis of variation in cyanogenesis among the southern populations showed a complex pattern, suggesting that there is no consistent trend related to their latitudes in the southern part of Japan. The result for the populations of Mt. Fuji indicated the presence of altitudinal cline for cyanogenesis; lower-altitudinal populations had higher frequencies of AcLi than higher-altitudinal ones. It was considered that this variation pattern was formed approximately within 30 years. Agronomic implications of AcLi are also discussed.

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This study was conducted to investigate the effects of the amount of cattle dung pat on the duration of dung patch existence. Fresh dung pats weighing 0.25, 0.5, 1.0 and 2.0 kg were artificially deposited on an Italian ryegrass (Lolium multiflorum Lam.) pasture, where it was thereafter rotationally grazed by Japanese Black cows. Control (no dung deposition) was set for comparison. The sward height was measured at three places (0-10, 10-30 and 30-50 cm) apart from the center of the dung pat, and changes over days in the dung patch areas were examined during dung patch existence. In all the dung treatments, the sward in the 0-10 or 10-30 cm place was taller than that in the 30-50 cm place around 35 days after the dung deposition, so that it was judged the dung patch was formed. The dung patch sward was taller in the places closer to the dung pat, and tallest on the 63rd day after the deposition. The duration of dung patch existence was evaluated at 2, 3, 4 and 6 months for 0.25, 0.5, 1.0 and 2.0kg treatments, respectively. In addition, it was suggested that the duration of dung patch existence was affected by weather, especially rainfall.

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In a previous paper we reported that nutrient deficiencies and plant-parasitic-nematodes were not major causes for the growth disorder observed in sorghum plants grown in the upland fields in Kagoshima and Miyazaki prefectures. As the next step we tried to determine the other factors causing this phenomenon in this study. It was suggested that soil microbes were a possible cause for the growth disorder, because soil treatments by fumigation of steam and chloropicrin were very effective against the disorder. However, the growth of sorghum was disordered by adding untreated or virgin soil to chloropicrin-treated soil. Moreover, the growth was greatly recovered by transplanting the affected plants to the virgin soil. This suggested that soil microbes were not main cause of the growth disorder of sorghum, implying the effects of un-known substances. Therefore, it was suggested that soil microbes, the exudate from the roots of sorghum and their joint action were possible causes for the growth disorder.

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As a part of the study on breeeding of timothy cultivars with high seed productivity, cultivarietal variations in seed yield and correlated characters, and the relationships between these characters were examined using 10 cultivars recently developed in Japan. Cultivarietal variation in seed yield was highly significant, and high seed yield was noted for cultivars that matured early. The correlation index of quadratic regression between seed yield and heading date (Values expressed as days from 1 June) was highly significant (-0.952, p<0.01) and the equation was found to be Y=0.011X^2-0.946X+21.821, where Y=seed yield and X=heading date. Cultivarietal variations in 10 characters correlated with seed yield except germination percentage were highly significant. The multiple correlation coefficient of number of spikes and seed weight per spike with seed yield was highly significant (0.992, p<0.01), and the multiple regression equation was found to be Y=0.009X_1+0.045X_2-3.984, where Y=seed yield, X_1=number of spikes and X_2=seed weight per spike. The path coefficient from seed weight per spike to seed yield exceeded that of number of spikes. It was suggested that the seed yield was more strongly affected by seed weight per spike than number of spikes.

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Geographic Information System and Digital Elevation Model were applied for an evaluation of pasture landscape. To analyze the spatial structure of landscape quantitatively, map database on test site was constructed. It expressed 4 indices, 1) Distance, 2) Visibility and invisibility, 3) Angle of depression or elevation and 4) Depth. The landscape of test site was analyzed as follows; i) The test site has 40.73km2 visible area. ii) View of west side is mountainous, and depth is perceptible by ridges. iii) View of north-to-east side does not have long distance landscape. iv) Though view of south-east side has long-distance landscape, it is not continuous from viewer point. These results agreed with the features of real landscape generally. It shows that this method is effective for landscape analysis.

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