In this study, effects of different sowing dates and seeding rates on N uptake efficiency (NUE), N translocation efficiency (NTE), agronomic efficiency (AE), physiological efficiency (PE), water use efficiency for grain yield (WUEg) and water use efficiency for biomass (WUEb) of facultative wheat were investigated. As the average of cropping year, sowing dates and seeding rates, N uptake efficiency (NUE), N translocation efficiency (NTE), agronomic efficiency (AE), physiological efficiency (PE), water use efficiency for grain yield (WUEg) and water use efficiency for biomass (WUEb) values were respectively obtained as 1.17?kg Nuptake/kg Napplied, 68.5%, 36.9?kg grain/kg Napplied, 31.2?kg grain/kg Nuptake, 5.19?kg ha?1 mm?1 and 18.04?kg ha?1 mm?1.
Nitrogen and water use efficiencies decreased with delayed sowing dates and increased with increasing seeding rates. It is possible to maintain a high wheat yield, nitrogen and water use efficiency by increasing plant density through winter sowing. It was concluded based on present findings that sowing date and seeding rates had significant effects on nitrogen and water use efficiencies and winter sowing should be practiced as not to cause yield losses and high seeding rates (575 seeds m?2) yielded greater nitrogen-water use efficiencies.
The oomycete pathogen Aphanomyces euteiches causes root rot in various legume species. In this study we focused on A. euteiches causing root rot in pea (Pisum sativum), thereby being responsible for severe yield losses in pea production. We aimed to understand the genetic diversity of A. euteiches in Europe, covering a north-to-south gradient spanning from Sweden, Norway and Finland to the UK, France and Italy. A collection of 85 European A. euteiches strains was obtained, all isolated from infected pea roots from commercial vining pea cultivation fields. The strains were genotyped using 22 simple-sequence repeat markers. Multilocus genotypes were compiled and the genetic diversity between individual strains and population structure between countries was analysed. The population comprising strains from Italy was genetically different and did not share ancestry with any other population. Also, strains originating from Finland and the eastern parts of Sweden were found to be significantly different from the other populations, while strains from the rest of Europe were more closely related. A subset of 10 A. euteiches strains from four countries was further phenotyped on two susceptible pea genotypes, as well as on one genotype with partial resistance towards A. euteiches. All strains were pathogenic on all pea genotypes, but with varying levels of disease severity. No correlation between the genetic relatedness of strains and virulence levels was found. In summary, our study identified three genetically distinct groups of A. euteiches in Europe along a north-to-south gradient, indicating local pathogen differentiation. 相似文献
We aimed to investigate whether sodium chloride seed priming and irrigation at seedling stage enhance response of 5-leaf stage tomato plants (Lycopersium esculentum Mill.) to high salt stress. Three experimental groups were as; non-primed seeds, seeds primed with 0.05M sodium chloride (NaCl), and seeds primed and irrigated with 0.05M NaCl starting from sowing to salt stress application. Sodium chloride solutions (0.1M, 0.2M, 0.4M, and 0.6M) were added to cups under pots in every 2 days for 10 days to treatment groups. Control groups were irrigated with distilled water at the same time intervals. At least two experimental setups contained at least four plants, and two samplings of leaf and root tissues were performed for analysis of each plant to evaluate changes in pigment and proline contents, lipid peroxidation and electrolyte leakage levels, and ascorbate peroxidase and catalase activity. Priming reduced mean germination time, and increased final germination percentage together with energy of germination. Increased root and hypocotyl lengths as well as increases in fresh weights supported enhanced seedling vigor. Considering growth and stress parameters such as chlorophyll content, chlorophyll to carotenoid ratios, and lipid peroxidation and electrolyte leakage were less affected in primed plants. Moreover, improvement of the accumulation of osmoregulating defense molecules, such as proline and anthocyanin, and of the inductions of the antioxidative enzyme system points out to higher adaptive response of these plants against deleterious effects of salt. 相似文献
Conflict over marine fishery resources is a growing security concern. Experts expect that global changes in our climate, food systems and oceans may spark or exacerbate resource conflicts. An initial scan of 803 relevant papers and subsequent intensive review of 31 fisheries conflict studies, focused on subnational and international conflicts, suggests that four substantial scientific gaps need addressing to improve our understanding of the nature and drivers of fisheries conflict. First, fisheries conflict and levels of conflict intensity are not precisely defined. Second, complex adaptive systems thinking is underutilized but has the potential to produce more realistic causal models of fishery conflict. Third, comparative large‐scale data and suitably integrative methodologies are lacking, underscoring the need for a standardized and comparable database of fisheries conflict cases to aid extrapolation beyond single case‐studies. Fourth, there is room for a more widespread application of higher order concepts and associated terminology. Importantly, the four gaps highlight the homogenized nature of current methodological and theoretical approaches to understanding fishery conflict, which potentially presents us with an oversimplified understanding of these conflicts. A more nuanced understanding of the complex and dynamic nature of fishery conflict and its causes is not only scientifically critical, but increasingly relevant for policymakers and practitioners in this turbulent world. 相似文献
Interactions between value-creating activities are vital to increasing product value. Information sharing is a cornerstone of such interactions. For a forest-owning company with the primary objective to be leading in selling roundwood to forest industries, it appears therefore crucial that the sales people within a forest company have up-to-date knowledge about the forest in planning their sales, and that the forest knowledge is presented in a format that is suitable for them. To investigate if this is the case, a study was conducted at Sveaskog, a large Swedish forest-owning company. Semi-structured interviews were conducted with respondents from different levels in the organization. The results show that most sales managers did not directly use the knowledge about the forests when planning their sales; instead, they relied on historical data and had low trust in the knowledge presented in the tactical forest plan. The study pinpoints the organizational obstacles for using forest information in sales planning. These obstacles need to be addressed if more sophisticated information made available through new technology is to be utilized. 相似文献