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排序方式: 共有66条查询结果,搜索用时 31 毫秒
21.
Kassu Tadesse Kassaye Almaz Admassu Tirfe Wubengeda Admasu Yilm Dawit Habte Haile Asrat Mekonnen Teto Amare Tadesse Weldegebriel 《Journal of plant nutrition》2013,36(19):2525-2535
AbstractSoil fertility depletion coupled with improper fertilization is one of the major constraints limiting linseed production in Ethiopia. Experiment was conducted in 2014/2015 on Nitisol in southeastern Ethiopian highlands to study the effect of phosphorus (P) fertilizer rate on yield, yield components, and oil content of linseed. It comprised of six levels of P fertilizer (0, 5, 10, 15, 20, and 25?kg?P?ha?1) arranged in randomized complete block design with three replications. Results revealed that P fertilization brought significant effect on biomass yield, harvest index, plant height, number of capsules per plant, and kernel size. However, it didn’t significantly increase seed yield and oil content on linseed. Considering its influence on increasing biomass yield and improving yield components, application of 5?kg?P?ha?1 has been recommended for replenishing the extracted P, maintaining soil fertility and improving linseed production on Nitisols of southeastern Ethiopian highlands and other similar agro-ecologies. 相似文献
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Hassen Chaka Tadesse Eguale Desalegn Lidetu Daniel Gizaw 《Tropical animal health and production》2009,41(6):973-978
A total of 54 lambs, aged between 6–8 months were experimentally infected with Haemonchus contortus to evaluate the efficacy of different anthelmintic brands sold on Ethiopian markets using the faecal egg count reduction test (FECRT) and controlled anthelmintic efficacy trial. Accordingly four different albendazole (Alzole®, Analgon-300®, Albenjung_s® and Ahshialben-300®), two tetramisole (Tetsole® and Ashitetra 600) and two tetramisole-oxyclozanide (Tetraclozan sheep® and Tetraclozash 900®) brands were evaluated at the dosage rates recommended by the manufacturers. Animals were allocated into nine groups of six animals each, and balanced for faecal egg counts (FEC), based on their pre-treatment FEC and treatments were randomized among the groups. One group was kept untreated as a control. Faecal egg count was conducted on day 30 post-infection (day of treatment) and on the 10th day post-treatment. Evaluation of anthelmintics based on FECRT revealed high efficacy (99.55–100% reduction in FEC) for all anthelmintic brands tested against H. contortus. The worm count reduction test using controlled anthelmintic efficacy trial also supported the above finding with 99–100% efficacy of the tested anthelmintics. Therefore, the suspicion on the anthelmintic products as being substandard in quality is not credible, at least, for the brands investigated in this study and it might rather be attributed to under dosing. The need for a good extension system for livestock producers with regard to good anthelmintic usage practices, in light of the inevitable development of anthelminitic resistance, is emphasized. Regular surveillance and laboratory quality evaluation of the anthelmintic products in Ethiopia is indicated. 相似文献
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Roba Yonas Tolosa Tadesse Daniel Assefa Zerihun Tesfaye Asamnew 《Tropical animal health and production》2020,52(6):3109-3112
Tropical Animal Health and Production - As per the report from the OIE in 2005, infectious laryngotracheitis (ILT) has not been yet reported in Ethiopia. Hence, considering the evident clinical... 相似文献
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Stein J Ayalew W Rege E Mulatu W Lemecha H Tadesse Y Tekle T Philipsson J 《Veterinary parasitology》2011,178(1-2):40-47
We conducted a two-part study in the native home areas of four cattle breeds, Abigar, Gurage, Horro and Sheko, in south-western Ethiopia. The first part of the study investigated livestock keeper knowledge about trypanosomosis and trypanotolerance. For each breed 60 livestock keepers were interviewed, resulting in a total of 240 interviews. The second part of the study focused on biological evidence for trypanotolerance. Blood samples of about 100 head of cattle per breed were collected during peak trypanosomosis challenge period and analyzed for packed cell volume (PCV) and parasitaemia. In addition individual body measurements of the sampled animals were taken and the keepers provided some information regarding their animals. Livestock keeper interviews revealed that trypanosomosis was considered a major problem in all areas (95-100%). Almost all Abigar livestock keepers knew how trypanosomosis is transmitted, whereas only 34-52% of the keepers of the other breeds had that knowledge. Most Sheko keepers (75%) knew of trypanotolerance and claimed to have trypanotolerant animals in their own herds. Among the other three breeds the knowledge of trypanotolerance was much less (8-18%). A majority of the keepers were interested in purchasing trypanotolerant animals. PCV was highest among Horro (26.2) and Sheko (25.1) cattle whereas Abigar had the lowest PCV (20.0). Sheko were least infected by trypanosomes (6%) and had the lowest number of trypanocidal treatments per year (1 treatment/animal and year). Abigar cattle were most infected (23%) followed by Gurage (20%) and Horro (17%). Gurage had by far the highest number of treatments per animal and year (24). There were large differences between the number of cattle perceived by the keepers to be infected, and the number detected from blood sampled, among Abigar, Gurage and Horro. Sheko livestock keepers were better at correctly diagnosing trypanosomosis in their animals. It is concluded that Sheko cattle have higher trypanotolerance attributes of the breeds investigated and a better use of this breed could improve cattle health and household welfare in tsetse-infested areas. 相似文献
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Predicting the potential distribution of invasive plants within a specific region is pivotal to planning effective management but is challenged by attempting to model expanding populations that are rarely at equilibrium with their environment. We adopt an ensemble modelling approach to assess the potential distribution of Japanese honeysuckle (Lonicera japonica), a vine invasive to forests of the Cumberland Plateau and Mountain Region in the southeast of USA. The influence of disturbance, spatial and temporal heterogeneity and other landscape characteristics were assessed by creating regional level models based on occurrence records from the United States Department of Agriculture, Forest Service, Forest Inventory and Analysis (FIA) database. Logistic regression and maximum entropy (MaxEnt) models were assessed independently and evaluated as predictive tools to test the value of presence/absence and presence only data in predicting species distributions. Ensemble models were also developed that combined the predictions of the two modelling approaches to obtain a more robust prediction. While logistic and MaxEnt models were similar in their predictive ability and dominant input variables, the ensemble approach derived the best fitting model overall. The regional distribution of Japanese honeysuckle was influenced greatly by environmental conditions such as elevation, slope, and temperature with anthropogenic activity having significant, though lesser, influence. The ensemble models predict that Japanese honeysuckle has nearly reached its potential distribution. However, given the critical role of minimum temperature on Japanese honeysuckle distribution, future occupancy at higher elevations is likely to increase since January temperatures for this region are predicted to rise by 1-4 °C over the next 100 years. The models also give some indication of the likely effect of land cover change on its distribution. Japanese honeysuckle tended to be associated with a high component of farming or low component of forest within the local neighbourhood. This suggests disturbed forest and/or high fragmentation has a higher invasion potential and given past trends and expected continued population growth this disturbance and fragmentation will only increase. The models can be integrated into forest management decision support systems and assist in the development of long term management plans, integrating the impact of potential climate and land cover change scenarios. 相似文献
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Agroforestry Systems - Conspicuous trees and other perennial plants in smallholders’ farms have been acknowledged for their biodiversity conservation values. Impacts of agroforestry... 相似文献
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W. Tadesse A. I. Morgounov H. J. Braun B. Akin M. Keser Yuksel Kaya R. C. Sharma S. Rajaram M. Singh M. Baum M. van Ginkel 《Euphytica》2013,194(2):177-185
The international winter wheat improvement program (IWWIP), an alliance between Turkey–CIMMYT–ICARDA, has distributed improved germplasm to different National Agricultural Research Systems (NARS) partners through international nurseries and yield trials for the last 25 years. This study was carried out in order to determine the rate of breeding progress for yield and yield related traits at IWWIP using data of the international winter wheat yield trials (IWWYT), IWWYT 1–13, collected from 1997 to 2010 in irrigated environments across different countries. The relative grain yield of the best line expressed as percent of the best check (Kinaci-97), widely grown cultivar (Bezostaya) and trial mean (TM) increased at a rate of 0.6, 1.6 and 0.2 %/year, each non-significant (P > 0.05), respectively. Regression analysis indicated that TM has increased at a rate of 91.9 kg/ha/year (P = 0.007). The net realized breeding progress was estimated by accounting the variability due to management and weather conditions using surrogate variables such as integrated biological indices taken as means of common checks. The net realized gain for the BL was 66.2 ± 19.7 kg/ha/year (P = 0.01). Success rate of the BL, per cent of sites where the BL exceeds the local check in grain yield, ranged from 50 to 87 % across trials. To date, more than 55 varieties of IWWIP origin have been released in 10 countries of Central and West Asia including Afghanistan, Turkey, Iran, Uzbekistan and Tajikistan. Some varieties, such as Solh and Kinaci-97, have been released under different names in different countries indicating their broad adaptation. Cluster analysis of IWWYT sites indicated that IWWIP sites in Turkey and Syria are associated with most of the testing sites in Central and West Asia and North Africa (CWANA) region. The recently identified high yielding genotypes are recommended for direct release and/or parental purposes by the respective NARS. 相似文献
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埃塞俄比亚东南部Dello Menna森林植被的植物区系和结构分析(英文) 总被引:2,自引:0,他引:2
描述了埃塞俄比亚东南部Dello Menna森林植被的植物区系组成和植被结构。鉴定和描述了50个20m×20m的样方的植物群落类型、物种多样性、丰富度和均匀性,分析了已鉴定植物群落类型与环境因子的相关性,还描述了木本植物种群结构。每个样方内,均记录木本植物的物种、丰富度、高度和胸径以及海拔、坡度。利用PC-ORD软件对植被进行分类。用Sorensen相似性系数探测群落之间的差异性。计算Shannon-Wiener多样性指数、物种丰富度、Shannon均匀性来描述各种植物群落的物种多样性。共记录了53个科的171个维管植物种。豆科植物是主要的优势植物科系,包括13个属26种(1 5%),其次依次是菊科、唇形科和槭树科,各包括8个物种(4.6%)。根据植物分类结果,识别并描述了3个植物群落(Dalbergia microphylla群落、Grewia bicolar-Acaciabrevispica群落、Combretum molle-Combretum collinum群落)。植物区系之间的物种丰富度、多样性和均匀性存在差异。物种丰富度和多样性随海拔变化呈现出贝尔型分布。群落间植物随海拔梯度有一定的变化,表明海拔是决定植物群落分布的重要因素之一。Dalbergia microphylla群落物种丰富度和多样性均最高。优势种群落结构呈现出各种模型。植被可持续利用是今后的研究方向。 相似文献