排序方式： 共有13条查询结果，搜索用时 93 毫秒
11.
Effect of nitrogen fertilizer application on growth, biomass production and N-uptake of torpedograss (Panicum repens L.) 总被引：1，自引：0，他引：1
MOHAMMAD AMZAD HOSSAIN YUKIO ISHIMINE HIKARU AKAMINE HITOSHI KURAMOCHI 《Weed Biology and Management》2004,4(2):86-94
A glasshouse study was conducted to evaluate the effects of different rates (0, 50, 100, 200 and 400 kg ha?1) of nitrogen (N) fertilizer application on the growth, biomass production and N‐uptake efficiency of torpedograss. The growth responses of torpedograss to the N application were significant throughout the observation periods. Torpedograss grown for 60 days obtained the highest total biomass of 23.0 g plant?1 with an application of 200 kg ha?1 N, followed by 20.4 g plant?1 with an application of 100 kg ha?1 N; when it was grown for 90 days a significantly higher biomass of 102.3–106.0 g plant?1 was obtained with the 200–400 kg ha?1 N than the biomass (68.0 g plant?1) obtained with the fertilizer applied at a lower rate. When the torpedograss was grown for 130 days the highest biomass was 230.0 g plant?1 with the 400 kg ha?1 N application, followed by a biomass of 150.0 g plant?1 with the 200 kg ha?1 N application, but the above‐ground shoot in all treatments was over mature for animal food. The ratio of the above‐ground shoot to the underground part increased with the increase in N application up to 400 kg ha?1 during the 90 days after planting (DAP), but the above‐ground shoot biomass was the same with the 200 and 400 kg ha?1 N. The agronomic efficiency of the N application decreased to 5–38 with the increase in N application to 400 kg ha?1, which was less than half the agronomic efficiency with the 200 kg ha?1 N. The agronomic efficiency of N was very low (5–22) during the 60 DAP, which indicated that the N application would not be economically viable in this period for torpedograss as a pasture, and short‐duration plants could be cultivated in torpedograss‐infested fields to minimize weed‐crop competition. The nitrogen concentration (%) in the torpedograss increased with the increase in N application, but N‐uptake efficiency was the opposite and the value was very low with the 400 kg ha?1 N. The above results lead us to conclude that the N application rate of 200 kg ha?1 is the most effective for torpedograss growth. 相似文献
12.
Mizuki KURAMOCHI Takeshi IZAWA Mayuka HORI Kayo KUSUDA Junichiro SHIMIZU Toshie ISERI Hideo AKIYOSHI Fumihito OHASHI Mitsuru KUWAMURA Jyoji YAMATE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):893-895
A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented
with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a
mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger
then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and
invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the
mass was composed of large, clear, vacuolated and polygonal cells with osteochondral
matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively
for cytokeratin and vimentin and negatively for S-100. Based on these findings, the
present case was diagnosed as a vertebral chordoma; the first report in a tiger. 相似文献
13.
MINORU ICHIHARA MASAYUKI YAMASHITA HITOSHI SAWADA YOICHI KIDA MOTOAKI ASAI 《Weed Biology and Management》2009,9(3):217-224
Italian ryegrass ( Lolium multiflorum Lam.) is an exotic winter annual weed that recently has seriously infested wheat fields in central Japan. To understand the influence of tillage systems on the germination ecology and seedbank dynamics of naturalized Italian ryegrass, we compared the fate of the seeds that were after-ripened in the soil with that of the seeds on the soil surface, and then examined the germination characteristics of the seeds retrieved from both treatments by germination tests in both a light/dark (12 h photoperiod) condition and in constant darkness. The seedling emergence was greater initially for the seeds after-ripened on the soil surface than for the seeds in the soil. The component of emergent seeds after-ripened on the soil surface increased as time passed during the summer, whereas that of emergent seeds in the soil scarcely increased. This contrasting emergence was, in part, attributable to the ability of the seeds to germinate at higher temperatures in the light/dark condition than in constant darkness. These results suggest that untilled systems, which leave many seeds on the soil surface, might promote the rapid depletion of Italian ryegrass seeds through germination before wheat sowing in early winter. In contrast, seed burial by tillage might inhibit the germination of the seeds and form a large transient seed bank available to germinate during the wheat-growing season. 相似文献