排序方式： 共有14条查询结果，搜索用时 781 毫秒
1.
The antigen detection enzyme immunoassay (AgELISA) in conjunction with parasitological examination of blood were used to study the enzootic situation of cameline trypanosomiasis in mid-Eastern Sudan. A one year survey showed that the infection is endemic among pastoral camels with a prevalence of 5.4% based on parasitological examination and 31.3% based on AgELISA. The infection rate was higher during the dry period (November to May) than the wet season. Young camels had a much lower infection rate as detected by parasitological techniques, but not with AgELISA. A lower prevalence of infection was detected by buffy coat technique (BCT) in herds of camels raised by nomads compared with those kept by agropastoralists and in camels located in the southern districts of mid-Eastern Sudan. 相似文献
2.
棘球蚴病是由细粒棘球绦虫的幼虫 (棘球蚴 )寄生在一些哺乳动物 (中间宿主 )体内而引起。本病遍布全球 ,在单峰驼中呈高水平的地方性流行 ,在流行地区 ,单峰驼是中间宿主。据报道 ,本病在单峰驼中的感染率为 1 7%～ 80 % ,在绵羊中的感染率为 1 .3%～ 2 0 %。细粒棘球绦虫在家畜体内一般有一个完整的生活周期 ,但在单峰驼体内这样一个周期却很少能够维持 ,因为 EIBiharl( 1 985 )证实 ,从感染的骆驼体内分离到的大部分是不育囊 (无原头蚴的囊 )。中间宿主可在出生后 ,采食或饮用含有细粒棘球绦虫虫卵的食肉目动物(终末宿主 )粪便污染的饲… 相似文献
3.
A total of 482 serum samples from pastoral camels in the Butana plains, mid-Eastern Sudan, were tested for Toxoplasma antibodies by the latex agglutination test (LAT). Sixty-seven percent of the camels were seroreactive. The prevalence rate of seroreactivity increased significantly with age (P less than 0.01) and was highest among camels aged over 7 years (74.2%). The prevalence rate of seropositivity decreased proportionally with the level of serum dilution. At dilutions of 1:32 and above, the prevalence rate was 25.9%. There were no sex-linked differences in seroreactivity. This study suggests widespread infection with Toxoplasma gondii among pastoral camels, a finding that warrants a closer look into the possible ways infection is acquired by camels in their arid environment, its economic impact, as well as its public health significance, especially among the nomads who consume cameline milk and liver raw. 相似文献
4.
Tomato plants were grown for 2 years at 4 different rates of Mg fertilization on a Princeton loamy sand at pH 4.8 with 29 kg exchangeable Mg/ha. Calcareous limestone was used to provide a pH treatment in the second year. Magnesium deficiency symptoms were observed on plants grown on plots having ≤ 38 kg/ha NH4OAC‐extractable Mg. Application of 56 kg Mg/ha corrected Mg deficiency and produced a significant increase in yield. Application of calcitic limestone also produced significant yield increases, but did not affect the development of Mg deficiency symptoms. Tomato yield was increased 27.9% by Mg application and 17.7% by lime application. Highest tomato yield was obtained with application of 112 kg Mg/ha. Symptoms of Mg deficiency were observed when the Mg concentration in recently mature leaf tissue was in the 0.30 to 0.32% range. Magnesium concentration in leaf tissue increased linearly with increasing Mg rate. Leaf Mg concentration at various growth stages of the tomato plant was variable depending on Mg treatment. Magnesium fertilization rate bad little effect on Ca or K leaf concentrations. Application of Calcltic limestone increased leaf tissue Ca and reduced leaf tissue Mg and Mn concentrations. 相似文献
5.
6.
Sandy clay soils locally known as gardud are less arable despite their better production potential than other infertile and exhausted sand soil in western Sudan due to surface physical constraints such as low infiltration and workability. Field experiments were, therefore, conducted on these soils to determine effect of two relatively new tillage systems to the area and two widely practised systems on soil bulk density, porosity, water storage and sorghum (Sorghum bicolor L.) plant growth and yield. Contour diking at specified spacings was superimposed on the four tillage treatments for impounding surface runoff. These systems were (1) chisel ploughing, (2) broadbed and furrow, (3) ridge-furrow, and (4) traditional no-till (control). Distances of the contour diking were at four levels: zero, 5, 10 and 20 m. Soil bulk density, porosity and water content were significantly affected by the different tillage systems and contour diking. Combined analysis of three successful seasons out of five seasons showed that plant establishment and growth were highly significant. Yield component data (percent of plants reaching physiological maturity, grain and straw) indicated significant differences among treatments tested for the three seasons of the experiment. The 3-year mean grain yield for chisel plowing pooled over the four contour diking distances produced 1448 kg/ha which was greater by 72%, 107% and 384% than broadbed and furrow, ridge-furrow and no-till, respectively. Similarly, the 10-m contour-diking-distance mean grain production (917 kg/ha) over the tillage systems was 16%, 5% and 30% for more than zero, 5-m and 20-m distances, respectively. These results indicate that chisel and 10-m contour diking are appropriate and suitable for gently sloping compacted sandy clay soils of western Sudan, and superior to widely practised ridge-furrow and no-till surface configuration. 相似文献
7.
M. A. El-Tilib E. A. Elamin M. M. El-Gaziri Y. E. El-Mahi 《Journal of plant nutrition》2013,36(9):1619-1632
A two-year field trial was conducted at Al-Marj Research Center, northeast Libya, during the summers of 1996 and 1997 to examine the effect of nitrogen (N) fertilizers on corn (Zea mays L.) growth in a Libyan soil (fine mixed thermic, Typic Haploxerolls) amended with different calcium carbonate (CaCO3) levels. Two N fertilizer sources (urea and diammonium phosphate, or DAP) were used at three application rates (0, 80, and 160 kg N/ha). The CaCO3 treatments were 1%, 6%, and 12% based on the soil weight of a 15 cm furrow slice. A basal phosphorus (P) dose of 46 kg P2O5/ha as triple superphosphate was applied to all experimental plots before planting. The experimental plots were arranged in a randomized split-split plot design with three replications. The parameters measured included corn grain weight, plant dry-matter content, leaf contents of N, P, potassium (K), calcium (Ca), and magnesium (Mg). The plant dry matter and corn-grain yield were significantly decreased by CaCO3, but were significantly increased by N fertilizer rates. Average grain yield dropped from 8 to 3 Mg/ha at 1% and 12% soil CaCO3 content, respectively. Generally, the N source did not have a significant effect on dry matter or on grain yield. The negative effect of CaCO3 on yield was associated with concomitant significant reduction in leaf N, P, K, and Mg contents, and an increase in Ca content. However, the leaf levels of these nutrients were considered sufficient for corn growth. Therefore, the reduction of leaf-N by CaCO3 in fertilized soils might have been the major cause of corn dry-matter and grain-yield reductions. 相似文献
8.
9.
10.