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51.
Abstract

Plant nutrition and disease suppression are among the most important management tools for producers of hard red winter wheat (Triticum aestivum L.) in the central and southern Great Plains. This study was conducted to examine the effects of phosphorus (P) (0, 15, and 30 kg ha?1) and potassium (K) (0, 37, and 74 kg ha?1) fertilization, foliar fungicide application, and cultivar disease tolerance on wheat yield, yield components, and severity of leaf rust (Puccinia triticina Eriks.). Compared with no P, fertilizing with P increased yield by as much as 60% (>1.3 Mg ha?1 increase). Yield of cultivars susceptible to leaf rust was nearly 0.6 Mg ha?1 less without K than with K fertilization. Fungicide application resulted in mean yields of 4.8 Mg ha?1 for both resistant and susceptible cultivars, however, yield of susceptible cultivars was suppressed more than yield of resistant ones without fungicide. Although P fertilization had a moderately suppressive effect on leaf rust, the increased yield was primarily due to production of about 50% more heads m?2 apparently from more prolific tillering. Similarly, K fertilization appeared to reduce leaf rust severity and improve yield by increasing kernel weight, but this response may have been related partially to chloride (Cl) in the KCl fertilizer. Correlations suggested that improving dry matter production and N, P, and K uptakes at the boot stage by P and K fertilization can reduce leaf rust severity later in the growing season and increase wheat grain yield. These results indicate that especially P fertilization, but also K fertilization and fungicide application, are important management tools for reducing disease and increasing winter wheat yield.  相似文献   
52.
In eukaryotes, termination of messenger RNA (mRNA) translation is mediated by the release factors eRF1 and eRF3. Using Saccharomyces cerevisiae as a model organism, we have identified a member of the DEAD-box protein (DBP) family, the DEAD-box RNA helicase and mRNA export factor Dbp5, as a player in translation termination. Dbp5 interacts genetically with both release factors and the polyadenlyate-binding protein Pab1. A physical interaction was specifically detected with eRF1. Moreover, we show that the helicase activity of Dbp5 is required for efficient stop-codon recognition, and intact Dbp5 is essential for recruitment of eRF3 into termination complexes. Therefore, Dbp5 controls the eRF3-eRF1 interaction and thus eRF3-mediated downstream events.  相似文献   
53.
The method of fertilizer nitrogen (N) application can affect N uptake in tall fescue and therefore its yield and quality. Subsurface-banding (knife) of fertilizer maximizes fescue N uptake in the poorly-drained clay-pan soils of southeastern Kansas. This study was conducted to determine if knifed N results in greater N uptake than the conventional top-dress application method in a deep, well-drained soil of east-central Kansas. The experiment, conducted in a Smolan silty clay loam soil, was a split-plot with fertilizer nitrogen rates 0, 140 and 280 kg N ha?1 applied as urea-ammonium nitrate (UAN, 28% N), knifed or top-dressed. Soil inorganic N [ammonium (NH4)- and nitrate (NO3–N)] and N in roots and plant tops were measured at various times during the growing season. At final harvest, most of the knifed N (99.7%) was accounted for in plant tissue (roots and tops) and soil, with more than half of the knifed N remaining as soil inorganic N. With the top-dressed method, 27% was unaccounted for and presumed lost in gaseous form. Knifing fertilizer N in fescue fields of east-central Kansas will maximize the availability of N, reduce potential N losses, and increase forage quality.  相似文献   
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56.
American Journal of Potato Research -  相似文献   
57.
We present epidemiological data from Bavaria that indicates that animals of the Brown Swiss (BS) cattle breed might be more susceptible to BSE than animals from other breeds, both in terms of disease prevalence and length of the incubation period. BS animals were disproportionately represented among the BSE cases (BS represented about 9% of the susceptible population but 27% of actual cases). BS were slaughtered at a higher age (5.8 years vs. 5.0 years for other breeds), and there is a higher prevalence of feeding proprietary feeds to BS calves than calves from other breeds. There was no difference in the recorded feeding practice of BSE-positive animals from BS or other breeds. These results would lead to expect a higher prevalence of BSE in the BS population, with BS BSE animals being of equal age or older than BSE animals from other breeds. In contrast, median age at BSE detection was significantly lower in BS animals than in other breeds (61.4 vs. 68.8 months). There was no difference in the identification categories of BSE between BS animals and animals of other breeds that could explain this difference in age. BS cattle are reported to have more octapeptid repeats in the prion protein gene than other breeds, which could account for shorter incubation periods and higher susceptibility. These observations suggest that BS animals and their tissues should be used in further studies into genetic determinants of BSE susceptibility in cattle.  相似文献   
58.
Coyotes from southern Alberta and Saskatchewan, Canada, were examined for the presence of Giardia and Cryptosporidium and cohabiting helminths. Toxascaris was present in over 90% of the 70 animals examined, and Taenia sp. in 6.5–25% of the two groups of animals studied. Giardia (12.5–21.7%) and Cryptosporidium (0–17.4%) were also common and molecular characterisation revealed both zoonotic and host-adapted genotypes of Giardia, whereas the Cryptosporidium proved to be a variant of the canine species C. canis. The seasonal variation observed in the occurrence of Cryptosporidium may be related to stress-induced shedding of the parasite.  相似文献   
59.
Every application of antibacterial drugs in veterinary medicine may encourage selection for resistant bacteria. In Germany no valid data are available which would be suitable for a species specific estimation of drug consumption especially regarding food producing animals. Therefore, a representative monitoring of consumption of antibacterial drugs in food producing animals should be implemented. As a first step, a feasibility project was conducted to identify the technical preconditions and develop a concept for a regular monitoring system within Germany as a country with a non-central federal state system. The data were collected via the forms obligatory by German law concerning the treatment of animals and the delivery of animal drugs to the animal owners by the veterinarian. 24 veterinary practices and 65 farmers were visited, and all applications of antibiotics to farm animals during the course of one year (September 1, 2006 to August 31, 2007) were entered into a central database. A total of 95,584 records were collected and analysed statistically. Consumption of antibiotics was calculated in kg, but also the number of applications was analysed. The consumption of tetracyclines in kg reached 54.3% of all antimicrobial substances applied to pigs, but only 25.7% of all doses applied to pigs were tetracyclines. For the farms' data, the number of daily doses per animal year (DD(ay)) was estimated based on the number of daily doses recorded and on the number of animals kept in the farm. Correct and detailed data regarding the structures of the farms as well as of veterinary practices are necessary to estimate the consumption of antibiotics reliably. The proposed system is able to function as a monitoring system for antibiotic use in Germany, when the monitoring data are linked to the agricultural data (farm sizes) accounting for differences between German regional agricultural and animal husbandry structures. Furthermore, the results of the antibiotic use analyses may serve as basis to assess the results of the sales data of the pharmaceutical industry. Results are comparable to the outcome of respective systems in other European countries, e.g. the Netherlands and Denmark, and therefore it will contribute to a better understanding and development of strategies for the control of antimicrobial resistances on the European level.  相似文献   
60.
The National Commission on Veterinary Economic Issues (NCVEI) is working to enhance the non-technical skills, knowledge, aptitudes, and attitudes (SKAs) of veterinarians. This report describes the development of an innovative model for teaching the principles of financial management as they apply to the veterinary practice. Zodiak: The Game of Business Finance and Strategy is a "business literacy" game in which players work together in small teams (generally four people) to run a fictional multi-million-dollar company called Zodiak Industries for three "years" in order to learn principles of business finance and strategy. After finishing the 4.5-hour game, participants spend the rest of the workshop making the right "Connections"-exercises designed to connect what they have learned to business strategies, financial statements, and operational tactics drawn from veterinary practice. Issues addressed for the veterinary practice, with parallels drawn to Zodiak, included return on owner investment in a veterinary practice (vs. salary drawn by owner veterinarians); pricing (setting prices, price elasticity of demand, and relationships between volume, quality, and price); human resources and operations management as they relate to profitability and efficiency; cash flow and management of accounts receivable; and commonly used financial benchmarks. Workshop venues have included Michigan State University, The Ohio State University, the University of Illinois, and Purdue University. Financial and in-kind support were provided through partnership with Pharmacia Animal Health (now Pfizer Animal Health) and Hill's Pet Nutrition, Inc. Through course evaluations, participants generally rated the workshop high as an educational experience and indicated that the most important things learned were related to financial management (principles, terminology, and methods). The most enjoyable aspects of the workshop tended to be group discussions, teamwork, the dynamic/interactive environment, and the "game" atmosphere. Based on these experiences, the Zodiak workshop provides a useful model for teaching career development and practice management topics to veterinary students. The business simulation in a workshop format was especially useful for teaching these "non-mainstream" topics, as traditional classroom lecture approaches might not have engaged students sufficiently to achieve effective learning. In addition, the partnership developed between academia and industry offered substantial benefits to both parties. Similar educational approaches should be considered for additional aspects of the non-technical SKAs.  相似文献   
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