Greenhouse gas emissions and energy use in UK-grown short-day strawberry (Fragaria xananassa Duch) crops

Original article can be found at: http://journals.cambridge.org/ Copyright Cambridge University PressReducing greenhouse gas emissions and optimizing energy consumption are important for mitigating climate change and improving resource use efficiency. Strawberry (Fragaria xananassa Duch) crops are a key component of the UK soft fruit sector and potentially resource-intensive crops. This is the first study to undertake a detailed environmental impact assessment of all methods of UK strawberry production. A total of 14 systems with six additional sub-systems grown for between 1 and 3 years were identified. They were defined by the growing of short-day (Junebearer) or everbearer varieties, organic production, covering with polytunnels or grown in the open, soil-grown (with or without fumigation) or container-grown (with peat or coir substrate) and summer or spring planted. Pre-harvest, the global warming potential varied between 1·5 and 10·3 t CO2 equiv/ha/crop or 0·13 and 1·14 t CO2 equiv/t of class 1 fruit. Key factors included the use of tunnels, mulch and irrigation, sterilization of soil with fumigants and the use of peat substrate. Seasonal crops without covers grown where rotation of sufficient length reduced Verticillium (system 4) were the most efficient. System 4a (that did not use mulch) emitted 0·13 t CO2 equiv/t of class 1 fruit. A second or third cropping year in soil-grown systems prolonged the effect of mulch and soil fumigants. Greenhouse gases from system 4 (with mulch) averaged 0·30 t CO2 equiv/t of class 1 fruit after 3 years of cropping compared to 0·63 and 0·36 t CO2 equiv/t after 1 and 2 years, respectively.Peer reviewe

Root‐lesion nematodes of potato: current status of diagnostics, pathogenicity and management

Root‐lesion nematodes of the genus Pratylenchus are migratory endoparasites with worldwide economic impact on several important crops including potato, where certain species like P. penetrans, P. neglectus and P. scribneri reduce the yield and quality of potato tubers. Morphological identification of Pratylenchus spp. is challenging, and recent advancements in molecular techniques provide robust and rapid diagnostics to differentiate species without need of specialist skills. However, the fact that molecular diagnostics are not available for all Pratylenchus species means that there are limitations in worldwide application. In general, root‐lesion nematodes are difficult to manage once introduced into agricultural land and damage can be related to pathogenicity and population densities. In addition, root‐lesion nematodes interact with fungi such as V. dahliae, resulting in disease complexes that enhance the damage inflicted on the potato crop. Management interventions are often focused on limiting nematode reproduction before planting crops and include the application of nematicides, and cultural practices such as crop rotation, cover crops, biofumigation, and biological control. Understanding the limitations of the available crop protection strategies is important and there are many gaps for further study. This review discusses the status of the diagnosis, distribution, pathogenicity and management of the main species of root‐lesion nematodes, reported to infect potatoes worldwide, and highlights areas for potential future research

Implications of railway relocation in Western Canadian cities : Saskatoon, a case study.

This thesis is a study of railway relocation and subsequent commercial redevelopment in Saskatoon, Saskatchewan. The primary purpose of the study is to test the hypothesis that railway relocation in a western Canadian city could prove beneficial to such a City in terms of community objectives. The City of Saskatoon is utilized as a case study. A secondary purpose, upon validation of the hypothesis, is to attempt the use of Saskatoon's experience as a bench-mark in determining the feasibility of railway relocation in other Saskatchewan cities. In order to place the City in its proper historical and developmental context, the history of Saskatoon is briefly traced from its origin in 1882 to the present. This review pictures Saskatoon as a dynamic urban center with a relatively bright future. A detailed review of events and negotiations leading up to the joint decision by the City and the C.N.R. to relocate railway facilities from downtown Saskatoon indicates that the primary community objectives involved were consolidation of the downtown area and improvement of access to the downtown area. These and other objectives are discussed in detail and analyzed in terms of their relevance and where possible, in terms of the magnitude of costs associated with achievement of a particular objective. The impact of the commercial development proposed for construction in the area vacated by the C.N.R. is demonstrated in terms of its effect on the supply of downtown retail space as opposed to the projected demand. On the basis of certain explicit assumptions, this analysis predicts an excess supply of retail floor space for a period of eight years. Quantifiable costs and benefits to the City attributable to relocation are compared with the resulting conclusion that, on the basis of current estimates, benefits accruing from relocation will yield a 9½% return on the City's investment by 1984. A subjective evaluation of non-quantifiable costs and benefits results in the further conclusion that benefits will again exceed costs. The aggregate conclusion, which validates the hypothesis, is that railway relocation in Saskatoon will prove beneficial to the City in terms of community objectives. The key factors which led to consideration of railway relocation in Saskatoon and which made the project viable were the dynamic nature of the city; the relative location of railway facilities; demand for retail space, and the location of railway rights-of-way relative to the location of required traffic facilities. These factors are tested against four other cities in Saskatchewan; Regina, Moose Jaw, Prince Albert, and Swift Current. Of the four, only Regina is consistantly comparable to Saskatoon, leading to the conclusion that detailed investigation of railway relocation from downtown Regina is warranted.It is further concluded that railway relocation from other Canadian cities might be equally feasible, and certainly worthy of further study.Applied Science, Faculty ofCommunity and Regional Planning (SCARP), School ofGraduat