To introduce perenniality into T. pratense, interspecific hybrids between T. medium (2n = 64 or 72) and 4x T. pratense (2n = 28) were produced. Female (T. medium) genotype affected the formation of embryos more strongly than male (T. pratense) genotype in the crosses. A total of 217 immature embryos were cultured on L2 media containing 12.5% sucrose, 0.02-0.2 mg/l 2,4-dichlorophenoxyacetic acid, 0.005-0.05 mg/l p-chlorophenoxyacetic acid, and either 0.4-10 mg/l adenine or 0.01-1.0 mg/l 6-benzylaminopurine. Nine hybrids were successfully grown to maturity. They had the expected chromosome number of 2n = 50. They showed the leaf marks and the notches at the tips of the standard petals which were expressed only by the male parent. Three of the plants had partial female fertility when backcrossed to 4x T. pratense and one of them produced rhizomes.

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Application of Italian ryegrass brown juice (BJ) either in organic or inorganic form, and with their various dilutions did not show any impact on corn crop growth in the glasshouse trials ; suggesting that the BJ could be applied safely as fertilizer material. As BJ contains some mineral components, the above result shows that its application will help depositing some amount of mineral in soil for successive crops and also to maintain soil fertility. However, significant result over the control could be obtained only in fermented and 10 times diluted BJ. Fermentation process yields high protein yeast product. Thus, recycling of BJ through fermentation route altogether will have a great effect on the economics of green crop fractionation process (GCF).

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Population dynamics of harvestable tillers and their generation after harvest were investigated on each cutting time of reed canarygrass (Phalaris arundinacea L.) swards that were grown under different cutting (3 and 4 cuttings per year) and nutrient (standard and low fertilization) treatments in 1984 and 1985 (Table 1). During two growing periods in 1984-1985, population of total productive tillers (TPT, the harvested tillers at each cutting) which consisted of both culm elongating (CET) and non-elongating (NET) tillers stayed rather invariable, fructuating around 800-900 shoots/m^2 in each sward with different cutting frequencies and nutrient levels (Table 3). In most cases TPT tillers composed of CET whose internodes had elongated above cutting height (5 cm above ground) ; the density of CET was at ca. 500 shoots/m^2 or more. On the contrary, NET was at lower level excepting that of last cutting in 4 C (cutting 4 times/year) swards with both nutrient levels. New tillers originated in abundance from the CET stubbles during ten days after each cutting, although their sprouting rate in autumn (especally that of last cuttings in 4 C swards) decreased to half. The underground new tillers UST, which had been dormant in the axils of underground stems of growing CET and started rhizomatous growth just after cutting, emerged with greater population, almost 3 times or more as compared with that of AST which sprouted from aerial nodes of the stubbles (Table 4). The dry matter yield of swards revealed high, positive correlations with plant height and mean dry matter yield per tiller, whereas it rather correlated negatively with TPT density (Fig. 1). Herbage production of reed canarygrass swards may be, therefore, exclusively dependent upon the leaf and internode growth of individual regrowing tillers, an essential and enough amount of which generates rather instantly and stably just after every cutting irrespective of growing seasons and managements.

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Dactylis glomerata is dominant species In the majority of improved pastures in cool-temperate zone of Japan. It is necessary to apply a large amount of soil amendment and chemical fertilizer to establish Dactylis glomerata. Zoysia japonica is dominant species in native pasture, and aggressively grows during summer even without fertilizer application. Zoysia pastures were widely distributed in the area from cool-temperate zone to warm-temperate zone in Japan. But utilization of the pasture is rapidly decreasing due to low productivity comparing with that of improved pasture. The purpose of the studies is to develope a method of establishing the association of Z. japonica and D. glomerata. The association will be promised a stable and low-input pasture for beef cattle in those mountainous areas. This report presented the effect of litter and fertilizer applicalion on the establishment of D. glomerata, Z. japonica and several weed species sunface-sown on the cut-over land in central Honshu of Japan. These weeds are typical species appearing on each stage of secondary succession in Japan. 1) D. glomerata seedlings were well established not only on the fertilized plots but also on non-fertilized plot. But the growth of seedlings established on litter covered seed-beds was higher than on litter removed seed-beds in all the fertilizer treatments plots. 2) Z. japonica seedlings were well established on the litter removed seed-bed in the non-fertilized plot. In order to keep a good population of both species, it is necessary to prepare the seed-bed without litter and without fertilizer application. 3) Setaria glauca appearing in the earliest stage of the secondary succesion was established well on non-fertilized plot. Therefore, the species is considered as plant for judging establishment of the Z. japonica-D. glomerata association.

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Effect of allotment of nitrogen (N) application on annual dry matter yield and dry matter yield of each hervesting time of three timothy (Phleum pratense L.) varieties were investigated to determine the best allotment for obtainning the highest yield of each variety. Tested timothy varieties were Kunpu, extremely early variety for use of three cuts, and Nosappu (early) and Hokushu (late) for use of two cuts, annually. Results obtained were summarized as follows : 1) Each cutting yield increased with higher application rates of N fertilizer. However, increase of yield was higher in the 1st cutting than in the 2nd or 3rd cutting. Therefore, annual yield was raised higher in the case that more rates of N fertilizer were allocated to the 1st cutting but more less to the 2nd or 3rd cutting, than in the case of splitting equally to each cutting. These tendencies were similar to all of three timothy varieties. 2) When the same rates of N fertilizer were applied to each cutting, the 1st cutting and 2nd cutting yields were higher than the 3rd cutting yield in Kunpu, and the 1st cutting yield was higher than the 2nd cutting yield in Nosappu and Hokushu. The dry matter production per 1 kg N absorbed by each variety was higher in the 1st cutting than the 2nd and 3rd cuttings. 3) The status of tiller development on which would influence the yield was differed among varieties tested here, namely, heading tillers at the 1st and 2nd cuttings for Kunpu and at the 1st cutting for Nosappu, and elongating tillers at the 1st and 2nd cuttings for Hokushu were important to increase each cutting yield. 4) The fall N application to Nosappu and Hokushu, accelerated to increase the number of their tillers and weight of leaves during the late fall and the next early spring, but was not resulted in increasing their 1st cutting at their heading stages. 5) From the results described above, under the conditions where the same annual rates of N fertilizer were applied, the best allotment application method of N fertilizer for the highest annual yield in each variety was clarified as follows : Kunpu was 3 : 2 : 1 = early spring : after the 1st cutting : after the 2nd cutting, and Nosappu and Hokushu were 2 : 1 = early spring : after the 1st cutting.

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The mode of inheritance of resistance to target leaf spot caused by Bipolaris cookei in sorghum was determined. Eight resistant (R) and susceptible (S) inbred lines were selected based on the results of preliminary seedling inoculation tests in a greenhouse. The lesions on the resistant lines were small, chlorotic and clearly different from the elongated ones on the susceptible lines. The results of the field test agreed with those of the greenhouse test, indicating that the seedling inoculation method was suitable for evaluating the resistance. Crosses were made between the selected inbred lines in the combinations of R × S, S × R, R × R, S × S and the F_1, F_2 and backcross progenies obtained were evaluated for resistance in the greenhouse. Most of the F_1, F_2 and backcross progenies segregated for resistance in a ratio expected for the resistance conferred by a single recessive gene. The results showed that the resistance to target leaf spot was controlled by a single recessive gene.

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High moisture (H-M, 18% dry matter) chopped silage, H-M unchopped silage, low moisture (L-M, 71% DM) silage, ammonia treated hay and field cured hay of first cut grass (timothy 70%, clover 30%) were prepared from the same field and fed to lambs to study the effect of fermentative quality of silage and ammonia treatment of moist hay on dry matter intake, animal growth and ruminant metabolism. H-M unchopped silage and hays were fed in chopped form. With H-M unchopped silage, large amount of butyric acid and ammonia was produced. The H-M chopped silage contained little butyric acid. The field cured hay contained more NDF and less CP than high moisture silage. TDN values were ranged from 61.4 for H-M unchopped (poor quality) to 71.0% DM for H-M chopped (good quality) silage. TDN value of ammonia treated hay was 64.9% DM and not significantly different from that of field cured hay. Nitrogen retention was highest for field cured hay. Dry matter intake for lambs fed H-M poor quality silage was only 2.3% of body weight and growth rate for five weeks was near zero. Lambs fed other forages consumed more than 3% of dry matter per body weight and gained about 10% of body weight. Feed efficiency (body weight gain/feed intake, %) of H-M poor quality silage was - 4.0%. Feed efficiencies of other forages were about 10% but that of H-M good quality silage was a little low. Ruminal ammonia concentration at 4 hr. post feeding were 20.4 mg/dl and 16.1 mg/dl for ammonia treated hay and H-M poor quality silage higher than for field cured hay and L-M silage. Feeding hays or L-M silage resulted in a high molar percentage of acetate in the rumen of lambs. Molar percentage of propionic acid in H-M good quality silage fed lambs was high. For H-M poor quality silage, ruminal butyric acid was higher and propionic acid was lower than other forages in each VFA. For lambs fed H-M poor quality silage, blood ketone level was high (10.2 mg/dl) and blood glucose level and blood protein level were low. Blood urea nitrogen levels were 28.5, 21.7 and 20.8 mg/dl for ammonia treated hay, H-M good quality silage and H-M poor quality silage higher than for field cured hay.

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The present study was conducted to investigate the effect of hybridization with Italian ryegrass (Lolium multiflorum LAM.) on the forage quality of tall fescue (Festuca arundinacea SCHREB.) cultivars. Six tall fescue cultivars (Kentucky 31, Manade, Maris Kasba, Tallmo, Pastuca and Yamanami) and their 29 intergeneric F_1 hybrids with Italian ryegrass (cv. Waseaoba) were grown under field conditions and harvested at the heading stage in the 1st and 2nd harvest years ; their neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin contents were compared. The NDF, ADF and lignin contents of Kentucky 31, Manade and Maris Kasba were decreased by hybridization with Italian ryegrass, whereas no definite changes in the contents were observed in Tallmo, Pastuca and Yamanami. On the basis of the results, it was concluded that the effect of hybridization on the forage quality likely varies among tall fescue cultivars.

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Leaf to stem ratio and nutritive values of these plant fractions are the contribution factors to nutritive values in whole plant herbage. This experiment was conducted to determine the response of leaf and stem fractions of green panic (Panicum maximum JACQ. var. trichoglume EYLEs) hay to ammonia treatment. Each of leaf and stem fraction separated by airflow segregation procedure was treated with 2.6% anhydrous ammonia (dry matter basis) and stored for 25 days anaerobically. Ammoniated and untreated hays were offered to four sheep ad libitum to assess intake, digestibility and nitrogen balance. Ammoniated hay was higher in content of CP and lower in contents of NFE, NDF and lignin than untreated hay. Leaf fraction had a higher content of CP, lower of NDF, ADF and lignin than stem fraction. Ammonia treatment improved the digestibility of dry matter, CP and CF, and increased DCP and TDN contents in leaf fraction, but dry matter digestibility and TDN content of stem fraction did not change. Ammoniation increased the intake of dry matter, DCP and TDN, and improved nitrogen balance irrespective of plant fractions. From these results it is evident that the response to ammonia treatment differed among fractions of grass hay.

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Ultraviolet spectrophotometric methods for quantitative determination of nitrate in plant materials is described. Plant material is extracted with 0.025 M Al_2 (SO_4)_3 containing 0.1% (W/V) sulfamic acid and oxidised activated charcoal. Nitrate in the extract is assayed using two methods. One is a single wavelength UV method (SWU method in Fig. 1), in which the absorbance of the extract is measured at 210 nm. Correction for the interference of nonnitrate species is made by subtracting the absorbance of the nitrate-free extract solution which has been treated with Zinc metal (sand form) to remove nitrate. The other is a dual wavelength UV method (DWU method in Fig. 1), in which the absorbance is measured at 225 nm. In this method, Correction for the interference is made by subtracting an empirically-determined multiple of the absorbance of the extract solution at 260 nm from its absorbance at 225 nm. The value of the multiplication factor is 7 for nine species of forages, 2.7 for Guineagrass, and 1.6 for spinach. The first method was readily adaptable for all plant species tested, but the procedure is slightly laborious. The second method is more simple, rapid and advantageous method, because there is no necessity of any chemical treatment to obtain a nitrate-free extract solution. But less accuracy was observed for the low nitrate-containing plant material, less than about 100 μg/g (0.01%, W/W) as nitrate-N.

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In the snowy area of Japan, the snow damage to the fences has been often found and all farm management costs on the public pastures has been oppressed by the fence maintenance cost. The fences of four types were tested for three years to grasp to the fences being low cost and little snow damage. Type I was the conventional fence with 4-barbed wire of the height of 30, 60, 90 and 120 cm above the ground and 4 meters post spacing, binding barbed wire on posts with 1.6 mm diameter wire. Type II had 4-barbed wire of the height of 30, 50, 75 and 110 cm and 4 meters post spacing, hanging barbed wire on posts with split cotter pins. Type III had 3-barbed wire of the height of 40, 70 and 110 cm and 9 meters post spacing using droppers at 3 meters interval. Type IV had 3-barbed wire of the height of 35, 65 and 95 cm and 25 meters post spacing using droppers at 5 meters interval. Wire tension was 20 kgf (196 N) for type I and II by hand, and 100 kgf for type III and IV by using strainers. In the fence maintenance, type I and II were left in the winter, but type III and IV were laid down all wire with droppers before winter and raised them in spring. The construction costs and maintenance costs of four types fences were compared for three years. The cattle escaping through the fences was not found. The maximum snow depth was observed 148 cm in Feb. of 1986, 90 cm in Feb. of 1987 and 100 cm in Feb. of 1988, respectively. As the snow settling force attacked barbed wire, the wire was broken or sagged in type I and II, breaking the wire to bind barbed wire and split cotter pins to hang one. In type III and IV, the snow damage was not found because of a lay-down system for all wire with droppers. In view of the comparison of fence costs, the construction costs could be reduced in case of increasing the post spacing and decreasing the numbers of barbed wire, and the maintenance costs could be reduced by layingdown wire with droppers as being no snow damage. Accordingly, it is recommended the lay-down fence like type III or IV in the snowy area. This lay-down fencing system is useful on the fiat pastures but may be difficult to stretch tightly barbed wire on the rolling or sloping pastures because the barbs on barbed wire often are caught on posts.

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An investigation was made into the return of dung to a bahiagrass pasture by Holstein heifers. Both daily excretion of dung dry weight and daily number of defecations were linearly and positively related to the daily dry matter intake of herbage and concentrate. Number of dung pats per defecation took relatively constant value (about 1.66). When the number of dung pats was counted dividing the pasture and resting place into 31 rectangles (about 60 m^2), proportion of dung pats to fall in each of the rectangles was explained by the distances between the rectangle and the resting place and between the rectangle and the opposite fence-line to the resting place. Both resting place and opposite fence-line to the resting place aggregated the dung pats. The dispersion pattern of dung pats within the rectangles of the pasture was in general well described by the Poisson distribution.

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