Chromosome number, method of reproduction and 26 morphological characteristics were investigated in 14 species of the genus Chloris. Chromosome numbers of the Chloris species were as follows; 2n=20: Chloris gayana Kunth, C. roxburghiana schult., C. pilosa Schumach. and C. virgata Sw.; 2n=40: C. gayana Kunth, C. pycnothrix Trin., C. acicularis Lindl., C. radiata Sw., C. polydactyla Sw., C. divaricata R. Br. and C. barbata Sw.; 2n=80: C. ciliata Sw. and C. distichophylla Lag.; 2n=100: C. castilloniana; 2n=120: C. truncata R. Br. Method of reproduction was studied by two techniques of embryo sac analysis and seed set tests. Embryo sac analyses showed that the species had sexual eight nucleate embryo sacs. Seed set data indicated that C. gayana (Rhodesgrass) is cross-pollinated and the other species are self-pollinated. Stern length, length and branch number of inflorescence and heading date in Chloris species showed wide variation. Among the species, C. gayana was taller and more vigorous than any other wild relatives. Tetraploid strains of C. gayana appeared to be giant types of diploid strains of C. gayana. Stomata of C. truncata (12x), C. castilloniana (10x), C. distichophylla (8x), C. ciliata (8x) and tetraploid C. gayana were significantly larger than those of any other diploid or tetraploid species. The relationships between ploidy levels and the other morphological characteristics were not always consistent. Cluster analysis was applied to numerical data of 26 morphological characteristics. Thirty four stains of 12 species tested were classified into 7 groups. Each group tended to have species with the same ploidy level.

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The objective of this study was to examine the varietal difference of tiller regrowth after defoliation in Sorghum species. 36 cultivars were grown in Sapporo in 1984. They were cut at 10 cm above the ground 75 days after sowing. On the 49th day after defoliation, dry weight of regrowth portion was the highest in the cultivars of S. bicolor × S. sudanense hybrid and S. sudanense. In those cultivars, most of the regrowth portion was the growth from new buds existing in the axils of the stubble, and the growth rate during the intial phase following defoliation was generally high (about 0.5g/day). The site usage (elongated buds/potential buds) 3 days after defoliation was greater in the cultivars of S. sudanense than in others, and more than 60% of potential sites developed into shoots. Over all cultivars, the dry weight of regrowth 3 days after cutting was not correlated with the dry weight of the stubble on the cutting day (r=0.086)^<N.S.>, but was correalted significantly with the site usage 3 days after cutting (r=0.871^<**>), and also with the number of the potential buds (r=0.591<**>). It was concluded from these results that the site usage was a important factor in determining the initial regrowth after cutting.

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This study was made to clarify the possibility of cultivation and use of Colombus grass (Sorghum almum Parodi.) in the warmer area of Japan. For this purpose, two cultivars of Colombus grass and three cultivars of Sudangrass (S. sudanense (Piper) Stamp) were compared from the aspect of HCN content, yielding ability, chemical composition and feeding values. The obtained results were as follows. 1) Total dry matter yields of J-Colombus and K-Colombus of Colombus grass were 224 and 250 kg/a, respectively and those of Piper, Hi-Sudan and Hay-Sudan of Sudangrass showed 185, 188 and 211 kg/a, respectively. These results suggested that Colombus grass had higher yielding ability than Sudangrass. 2) The HCN content in Colombus grass was higher than that in Sudangrass. Among cultivars of Colombus grass, J-Colombus showed higher HCN content than K-Colombus. On the other hand, among cultivars of Sudangrass, Hi-Sudan showed the highest HCN content and Hay-Sudan followed and Piper showed the extremely low potential. Considering from the safety limitation of HCN being below 500 ppm on dry matter basis and from the relationship between the dry matter and plant length, the plant length should be over 110 and 140 cm for K-Colombus and J-Colombus in cultivars of Colombus grass, respectively. 3) The experimental results of digestion trial from sheep showed that the crude fiber of Colombus grass was digested much easier than that of Sudangrass. The contents of digestive nutrients of both grasses were as follows : DCP and TDN contents in the first crop of K-Colombus were 9.5 and 59.6%, respectively, and those in the second crop were 4.6 and 58.3%, respectively. These contents in Hi-Sudan were 9.9 and 54.4% in the first crop, respectively and 6.7 and 54.9% in the second one, respectively. 4) The above results indicate that Colombus grass is superior to Sudangrass in yielding capacity and digestibility of crude fiber, but it is important to pay attention to the desirable mowing time then HCN content in shoots is below poisoning level. Since Colombus grass is wet tolerant, this grass is considered to be useful in the future for a new green fodder crop to the rotational paddy field in the warmer area of Japan.

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Near infrared reflectance spectorscopy (NIR) was used to predict chemical composition of forage samples. Separate calibration for each of corn silage, hay, grass silage, mixed grass hay and grass silage were developed with 388 samples in total. In addition to these samples, 124 forage samples including corn silage, mixed hay, grass silage and sorghum silage were used to test the calibration equations. Percent crude protein (CP), ether extract, crude fiber (CF), acid detergent fiber (ADF), organic cellular contents (OCC), organic cell wall (OCW), high digestible fiber fraction (Organic a fraction, Oa), low digestible fiber fraction (Organic b fraction, Ob) and starch were analyzed for these forage samples. Accuracy of the predictions was assessed by the correlation coefficients (r) and the standard error (Se) of the estimate. The r and Se values of hay were 0.98 and 0.96% for CP, 0.79 and 2.95% for CF, 0.92 and 2.44% for OCC, 0.91 and 3.02% for OCW, 0.81 and 4.80% for Ob, 0.74 and 2.44% for ADF, respectively in prediction. Similar values were also observed in grass silage. Corn silage samples, however, showed slightly lower r and higher Se values as compared with hay samples used in our studies. These results indicated that moisture, CP, CF, OCC, OCW, Ob and ADF contents in forage samples can be predicted by using NIR techniques with an acceptable accuracy.

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The lignin content of three grasses and alfalfa samples of known in vivo dry matter digestibility was determined by two different methods ; the acid detergent method (successive treatment with acid detergent and 72% sulfuric acid) and the pronase method (successive treatment with pronase and 72% sulfuric acid). The lignin content determined by the acid detergent method was lower than that determined by the pronase method for all the samples. The difference in the lignin content determined by the two methods was much greater in the grass sample than in the alfalfa samples. It was concluded that the acid detergent treatment overestimated the difference in the lignin level between grasses and alfalfa with the same digestbility.

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It was studied to evaluate the influence of infection of spring black stem fungus Phoma medicaginis Malbranche et Roumeguere on the feed composition and nutritive value of alfalfa (Medicago sativa L.). The investigation was carried out on the samples from variety-test-fields of the National Institute of Animal Industry, Chiba in 1970 and the Aichi-ken Agricultural Research Center, Aichi, Japan in 1975. The disease severity of alfalfa spring black stem was higher in southern habitat origin varieties (I-Group) than in northern origins (IV or V-Group). This result was correspondingly with the data of FUKUSHIRO and FURUTA (1985). The health and diseased samples were collected from each variety for determination of feed composition and evaluation of nutritive value. In alfalfa varieties, Sonora and Du Puits, which shown high disease severity, contents of crude protein, soluble carbohydrate, crude fat, dry matter digestibility, total digestible nutrient and digestible crude protein were lower in the diseased sample than healthy. The change of nutritive quality in alfalfa variety Rhizoma which indicated low disease severity of spring black stem was not clear. The results were the same as on the two experimental field or in different year. These results indicate that the severe spring black stem infection cause considerable qualitative damages on the alfalfa.

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In November 1972, orchardgrass (Dactylis glomerata L.) was infected with stem rust (Puccinia graminis Persoon subsp. graminicola Urban) at field in National Grassland Research Institute, Nishinasuno, Nasu, Tochigi, Japan. It was attempted to determine the influence of stem rust on feed composition and nutritive values of cutting whole leaves of orchardgrass. Fresh weight of much-diseased cutting reduced to about 70% of less-diseased one. A lot of severe infected leaves (disease severity index III-V) occupied only 12.3% of fresh weight in less-diseased cutting, while it reached to 50.6% in much- diseased. Dry matter yield was equal in two cutting. Dry matter digestibility was 66.5% in the less-diseased, but it was 60.0% in the much-diseased. The percentage of crude protein, crude fat, soluble carbohydrate, sodium, manganese and copper decreased, while ash, crude silicate, fiber (NDF, ADF and Hemicellulose), lignin, potassium, magnesium and iron increased in much-diseased. The results show that the cutting whole leaves of orchardgrass containing a number of severe infected leaves with stem rust fungus suffered a considerable damage on their qualitative values. Regression equation between the diseased area and nutritive value of the leaves was made in order to estimate the nutritional deterioration of the orchardgrass from the severity of the stem rust.

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Palatability, chemical composition and in vitro dry matter digestibility (IVDMD) were studied to determine the influence of cultivar and the length of weathering period on the feeding value of sorghum foggage. Cultivar "SS IV", "C 7149 P", "P 988" and "P 956" were at the dough stage on October 23, and they had relatively much grains before weathering as shown in the proportions of the head, leaf blade and stem (including sheath) ; 27.6-11.4-61.0% (SS IV), 20.8-13.7-65.5% (C 7149 P), 25.5-13.9-60.6% (P 988) and 44.1-11.6-44.3% (P 956), respectively. On the contrary, "P 931" and "FS 401 R" were at the boot and the pre-flowering stage on October 23, and relatively leafy as shown in the proportions of three plant parts ; 2.0-26.8-71.2% (P 931) and 7.1-23.0-69.9% (FS 401 R), respectively. Further photosynthetic accumulation of soluble carbohydrates were gained on all sorghums for a long term after maturation (8.0% unit increase of WSC content from Oct. 23 to Nov. 20), being accompanied by some improvement of IVDMD. However, as the weathering went on, a little decreases of crude protein and fat contents were observed in all sorghums, while soluble carbohydrates contents, cell wall constituents and IVDMD remained less variable. "SS IV", "C 7149 P", "P 988" and "P 956" showed 35.5% decrease of the dry matter weight per plant, and "C 7149 P" and "P 956" also decreased the palatability during weathering, mainly because the grains were lost with bird-picking and shedding. On the contrary, "FS 401 R" yielded a relatively high dry matter weight per plant and retained the dry matter weight and leafness. "FS 401 R" was higher in soluble carbohydrates contents, IVDMD and palatability during weathering. Based in the present results, the sorghum foggage may be a useful feedstuff for cattle. In particular, "FS 401 R" would be recommended for the foggage making, in terms of both feeding values and utilization time. Sorghum cultivar with much grains should be limited to use in earlier weathering period.

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Germinating behaviors of tall fescue (Festuca arundinacea Schreb., variety "Kentucky 31") were observed to characterize the establishment of grass seedling grown on the smooth surface. The seeds were allowed to germinate under the controlled conditions with a constant temperature of 30℃ and a RH of approximately 100%. 1. At the initial stage of germination, the coleorhiza which had columnar-shaped with the tip rounded, appeared at the basal portion of lemma prior to develop numerous hairs around the tip (Fig. 2). 2. The coleorhiza hairs adhered to the surface of seed bed and subsequently anchored to the surface. When anchored well, the seed rose up owing to some growth in the ventral portion of coleorhiza. In this case, a germinating process passed favourably, because the seminal root of seed could penetrate into the soil directly below the coleorhiza (Figs. 3 and 4). 3. However, if the coleorhiza hairs failed to adhere to the seed bed, seeds did not rise up and thus the seminal root of the seed failed to penetrate into the soil. Sometimes the elongating seminal root was forced the seed push back from penetrating point of root tip (Fig. 3). 4. The adhering strength of coleorhiza hairs was expressed as maximum tensile load to pull out a seed from soil surface. The strength was positively related to the volume of clod which the hair bound the surface soil (r=0.89, p<0.001). The average of this figure in the rising seed was 2.66 gr, and was about 550 times as much as the weight of swelled seed (Figs. 5,6 and Table 1). 5. Based on the present results, an adhering function of coleorhiza hairs would physically support good establishment of seed when sown on the soil surface.

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Pasture renovation by using herbicides and direct drilling offers potential advantages over the conventional plowing methods in terms of reducing energy and labour requirements. Generally, rhizomatous grasses such as the Kentucky bluegrass or redtop are difficult to suppress using herbicides. However as the action mechanisms are widely different among herbicides, it will be possible to find out more suitable method to suppress these rhizomatous grasses. The effectiveness of paraquat and glyphosate was compared with the suppression by plowing or mowing, on the Kentucky bluegrass and redtop dorminant pasture for two years in field studies. The amount of 76 and 36 g/10a (active ingredient) of paraquat was sprayed on 12th and 16th July, and 356 g/10a (active ingredient) of glyphosate on 6th July, 1984. After the herbicides spraying, the mixture seeds of orchardgrass, meadow fescue and ladino clover were drilled by the Powertill Seeder, at the spacing of 20 cm intervals on 21st July. Parquat application or the mowing could not suppress the regrowth of the Kentucky bluegrass and redtop effectively. Therefore, establishment of drilled pastures were not successful in the second year under grazing condition. On the other hand, glyphosate application suppressed these grasses effectively, and the drilled pastures were established well. However, the drill seeding of 20 cm intervals after glyphosate application had left bare ground between rows, and this bare ground resulted in lower yield. Therefore, the improvement of the drill seeding interval is considered to be important.

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Effects of glyphosate were investigated for the suppression of the rhizomatous grasses dominant pasture. The amount of 0,89 and 178 g/10a (active ingredient) of glyphosate were sprayed on June, July, August and September. Further treatments of 8, 36, 53 and 71 g/10a applications were added on September. With application of glyphosate until August, seeded pastures will be established successfully within the same year. After September spraying, the successive seeding should be done in next spring. The effect of the grass suppression by the summer spraying was greater on August and followed by July and June. The later the time of application, the smaller the amount of dose needed. When sprayed on July and August, minimum amount for suppression were 178 and 89 g/10a, respectively. The autumn spraying was more effective than the summer spraying. On September, the application of 71 g/10a was effective. And the autumn spraying has another merit, that is, the pasture can be utilized till the beginning of autumn.

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Orchardgrass (Dactylis glomerata L. CV. Aonami) was grown under the different potassium levels by water culture method and the growth response to potassium was investigated. The results were as follows; The plant growth and the potassium concentration in orchardgrass clearly responded to the potassium, although the response distinctly depended on the different levels of potassium in culture solution. In the lower potassium levels, there was a significant increase of the plant yield with increase of potassium level without any change of potassium concentration in plant, while in the higher levels there was a significant increase of potassium concentration in plant with increase of potassium level without any increase of plant yield. Moreover in the excessive levels of potassium in culture solution, plant growth and potassium uptake were restricted. The potassium concentration in the plant well responded to the increase of fresh yield until it reached up to 3 per cent of potassium on a dry matter basis, while the higher concentrations than 3 per cent of potassium did not result in the increase of plant growth. It was clearly recognized that the excessive increases of potassium concentration in the plant resulted in the decrease of calcium and magnesium concentrations in the plant.

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Higher plants have cuticular structure on the surface of aboveground organs. The structure penetrates light onto the photosynthetic tissues, but it is waterproof with wax-like substances. By this structure, plants are protected from wind, frost damage and exposure of solar radiation and increase tolerance against insect-damages and infections by fungous diseases. In the course of the authors' research work on fine surface structures of seed coats of forage crops and wild grasses, glumes were found to have protruding architectures on the cuticular wax. Fine surface structures of the glumes using thirteen species belonging to Gramineae were further examined to compare their shapes and some chemical characters by scanning electron microscope.

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