1,631 research outputs found

    Yield losses caused by late blight (Phytophthora infestans (Mont.) de Bary) in potato crops in Ireland

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    peer-reviewedField experiments, using foliage blight susceptible cultivars, were conducted at Oak Park, Carlow from 1983 to 2007 to determine the loss in potato production caused by crop infection with Phytophthora infestans. In each of the 25 years an untreated control was compared with protectant and with systemic fungicide programmes to determine the effect of late blight on the defoliation percentage at the end of the season, the area under the disease progress curve, marketable tuber yield, total tuber yield and yield of blighted tubers. The earliest date of first recorded late blight was 22 June and the latest was 15 September, but in 15 of the 25 years, blight was first recorded between 17 July and 13 August. Disease reached epidemic proportions in all but 4 of the years. Yields varied considerably among years. The mean loss in total yield from not using a fungicide was 10.1 t/ha. Differences in yield were significant across the 25 seasons. No overall increase in aggressiveness of the pathogen could be detected over the 25-year period

    Occupational fatalities amongst farm workers in Ireland, 1992 – 2008

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    working paperBackground: Whilst occupational fatalities amongst farm workers have been studied internationally little research has been published concerning farm fatalities or the demography farm fatalities in Ireland. Aims 1) To establish the incidence of farm fatalities during the 1992 – 2009 period in Ireland, 2) to explore the changing age profile of those experiencing fatal injuries on farms in Ireland. Methods: An official dataset containing the details of every fatal farm accident during the 1992 – 2009 period is used to evaluate changes in the number and age profile of farm fatalities in Ireland. Results: There were 304 deaths on farms during the 1992 – 2009 period in Ireland. The average number of annual fatalities is declining having fallen by 16% from 18 to 16 per year during this time. The fatality rate has however increased from 15 to 22 per 100,000 workers. This has been driven by a reduction in the number of workers employed on farms and, it is hypothesised, rapid ageing of the farm workforce. The demographic profile of those killed on farms changed significantly over the period. There are fewer deaths amongst younger cohorts. Older farmers, those over 55 years of age, now account for the vast majority of all fatal accidents. Conclusion: These findings highlight the changing nature of fatal farm incidents over the 1993 – 2009 period in Ireland. The increasing number of fatalities amongst older farmers suggests that Ireland’s Farm Safety Partnership needs to place greater emphasis of raising awareness amongst older farmers of fatality risks

    Coupled Fluids-Radiation Analysis of a High-Mass Mars Vehicle

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    The NEQAIR line-by-line radiation code has been incorporated into the DPLR Navier-Stokes flow solver such that the NEQAIR subroutines are now callable functions of DPLR. The coupled DPLR-NEQAIR code was applied to compute the convective and radiative heating rates over high-mass Mars entry vehicles. Two vehicle geometries were considered - a 15 m diameter 70-degree sphere cone configuration and a slender, mid-L/D vehicle with a diameter of 5 m called an Ellipsled. The entry masses ranged from 100 to 165 metric tons. Solutions were generated for entry velocities ranging from 6.5 to 9.1 km/s. The coupled fluids-radiation solutions were performed at the peak heating location along trajectories generated by the Traj trajectory analysis code. The impact of fluids-radiation coupling is a function of the level of radiative heating and the freestream density and velocity. For the high-mass Mars vehicles examined in this study, coupling effects were greatest for entry velocities above 8.5 km/s where the surface radiative heating was reduced by up 17%. Generally speaking, the Ellipsled geometry experiences a lower peak radiative heating rate but a higher peak turbulent convective heating rate than the MSL-based vehicle

    Integrated environmental control in mushroom tunnels.

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    End of Project ReportThe main objective of this investigation was to achieve improved control of the micro-climate around the mushroom crop. The work was based on two approaches. One, which required the greater part of the work, was gaining an understanding of the characteristics/physics of the climate control system as a whole within mushroom tunnels and the other was the application of modern control strategies to manipulate more effectively the conditions at the cropping surface. The work showed that the influences of the operation of the air conditioning on the crop micro-climate was far greater than the expected adjustment of, say, temperature and that novel systems and improved measurement of the micro-climate were required in order to optimise the control of air conditions. The operation of the heating system caused a load dependent, i.e. seasonal, variation in the average drying power of the air at the crop. While heating (on/off control) was in operation, air flow effectively ceased at the cropping surface and the effect persisted for the duration of the heating and a recovery period afterwards. Various simple strategies could be implemented to minimise these effects but a novel design for air distribution provided a means of eliminating the effect. Because of the complex relationship between the delivery of conditioned air and the consequent flow at the cropping surface, improved feedback from the crop micro-climate was found to be essential for improved control. A new sensor was developed in conjunction with the Department of Electronic Engineering, NUI Galway that provided a low cost measurement of the very low air speeds used in mushroom growing. The Irish mushroom-growing system (bags and tunnels) offers more potential for accurate control than other, tiered, growing systems. The goal of the second aspect of this project was the provision of an accurate and robust control system for mushroom tunnels. Work focused on the control relationships between inputs and outputs of the system. A Teagasc Walsh Fellowship supported the early work which was carried out in conjunction with the Department of Electronic Engineering at NUI, Galway. Initial work prior to this project, with control specialists in DIT, Kevin Street College of Technology, was extended to provide a mathematical/control model of the main physical processes involved. A second Walsh Fellowship supported a link with the control systems group in the Department of Electronic Engineering, Dublin City University and allowed further control studies in mushroom tunnels.European Union Structural Funds (EAGGF)Teagasc Walsh Fellowship Programm

    Examination of Production Systems for Mushroom Cultivation in Ireland

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    End of Project ReportThe plastic bag growing system used in Ireland is very labour intensive requiring considerable manual labour input. This has several very undesirable consequences. It was because of these considerations that it was considered important to examine possible feasible alternatives to plastic bag production for the Irish Mushroom Industry. This project was set up at Kinsealy Research Centre to examine possible alternatives. Part of this consisted of examining commercial systems both at home and abroad

    Implementing biosecurity measures on dairy farms in Ireland

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    peer-reviewedDairy farms in Ireland are expanding in preparation for a new era of unrestricted milk production with the elimination of the European Union (EU) production quotas in 2015. Countries experiencing a changing agricultural demographic, including farm expansion, can benefit from documenting the implementation of on-farm biosecurity. The objectives of this study were to document and describe influences on biosecurity practices and related opinions on dairy farms. A representative response rate of 64% was achieved to a nationwide telesurvey of farmers. A 20% discrepancy was found between self-declared and truly ‘closed’ herds indicating a lack of understanding of the closed herd concept. Although >72% of farmers surveyed considered biosecurity to be important, 53% stated that a lack of information might prevent them from improving their biosecurity. Logistic regression highlighted regional, age, and farm-size related differences in biosecurity practices and opinions towards its implementation. Farmers in the most dairy cattle dense region were three times more likely to quarantine purchased stock than were their equivalents in regions where dairy production was less intense (P = 0.012). Younger farmers in general were over twice as likely as middle-aged farmers to implement biosecurity guidelines (P = 0.026). The owners of large enterprises were almost five times more likely to join a voluntary animal health scheme (P = 0.003), and were over three times more likely to pay a premium price for health accredited animals (P = 0.02) than were those farming small holdings. The baseline data recorded in this survey will form the basis for more detailed sociological and demographic research which will facilitate the targeting of future training of the farming community in biosecurity

    Exploring the relationship between groundwater geochemical factors and denitrification potentials on a dairy farm in southeast Ireland

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    NOTICE: this is the author’s version of a work that was accepted for publication in the journal Ecological Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Ecological Engineering, volume 37, issue 9, September 2011, 1304-1313. DOI: 10.1016/j.ecoleng.2011.03.025peer-reviewedNitrate (NO3−) loss from agriculture to shallow groundwater and transferral to sensitive aquatic ecosystems is of global concern. Denitrifying bioreactor technology, where a solid carbon (C) reactive media intercepts contaminated groundwater, has been successfully used to convert NO3− to di-nitrogen (N2) gas. One of the challenges of groundwater remediation research is how to track denitrification potential spatially and temporally within reactive media and subsoil. First, using δ15N/δ18O isotopes, eight wells were divided into indicative transformational processes of ‘nitrification’ or ‘denitrification’ wells. Then, using N2/argon (Ar) ratios these wells were divided into ‘low denitrification potential’ or high denitrification potential’ categories. Secondly, using falling head tests, the saturated hydraulic conductivity (Ksat) in each well was estimated, creating two groups of ‘slow’ (0.06 m day−1) and ‘fast’ (0.13 m day−1) wells, respectively. Thirdly, two ‘low denitrification potential’ wells (one fast and one slow) with high NO3− concentration were amended with woodchip to enhance denitrification. Water samples were retrieved from all wells using a low flow syringe to avoid de-gassing and analysed for N2/Ar ratio using membrane inlet mass spectrometry. Results showed that there was good agreement between isotope and chemical (N2/Ar ratio and dissolved organic C (DOC)) and physio-chemical (dissolved oxygen, temperature, conductivity and pH) parameters. To explain the spatial and temporal distribution of NO3− and other parameters on site, the development of predictive models using the available datasets for this field site was examined for NO3−, Cl−, N2/Ar and DOC. Initial statistical analysis was directed towards the testing of the effect of woodchip amendment. The analysis was formulated as a repeated measures analysis of the factorial structure for treatment and time. Nitrate concentrations were related to Ksat and water level (p < 0.0001 and p = 0.02, respectively), but did not respond to woodchip addition (p = 0.09). This non-destructive technique allows elucidation of denitrification potential over time and could be used in denitrifying bioreactor technology to assess denitrification hotspots in reactive media, while developing a NO3− spatial and temporal predictive model for bioreactor site specific conditions

    Meeting the problems and needs of resident advisory groups

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    ii, 74 l. 28 cm

    Coupled Fluids-Radiation Analysis of a High-Mass Mars Entry Vehicle

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    The NEQAIR line-by-line radiation code has been incorporated into the DPLR Navier-Stokes flow solver such that the NEQAIR subroutines are now callable functions of DPLR. The coupled DPLR-NEQAIR code was applied to compute the convective and radiative heating rates over high-mass Mars entry vehicles. Two vehicle geometries were considered - a 15 m diameter 70-degree sphere cone configuration and a slender, mid-L/D vehicle with a diameter of 5 m called an Ellipsled. The entry masses ranged from 100 to 165 metric tons. Solutions were generated for entry velocities ranging from 6.5 to 9.1 km/s. The coupled fluids-radiation solutions were performed at the peak heating location along trajectories generated by the Traj trajectory analysis code. The impact of fluids-radiation coupling is a function of the level of radiative heating and the freestream density and velocity. For the high-mass Mars vehicles examined in this study, coupling effects were greatest for entry velocities above 8.5 km/s where the surface radiative heating was reduced by up 17%. Generally speaking, the Ellipsled geometry experiences a lower peak radiative heating rate but a higher peak turbulent convective heating rate than the MSL-based vehicle

    Identification of possible cow grazing behaviour indicators for restricted grass availability in a pasture-based spring calving dairy system

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    peer-reviewedPrecision livestock farming uses biosensors to measure different parameters of individual animals to support farmers in the decision making process. Although sensor development is advanced, there is still little implementation of sensor-based solutions on commercial farms. Especially on pasture-based dairy systems, the grazing management of cows is largely not supported by technology. A key factor in pasture-based milk production is the correct grass allocation to maximize the grass utilization per cow, while optimizing cow performance. Currently, grass allocation is mostly based on subjective eye measurements or calculations per herd. The aim of this study was to identify possible indicators of insufficient or sufficient grass allocation in the cow grazing behaviour measures. A total number of 30 cows were allocated a restricted pasture allowance of 60% of their intake capacity. Their behavioural characteristics were compared to those of 10 cows (control group) with pasture allowance of 100% of their intake capacity. Grazing behaviour and activity of cows were measured using the RumiWatchSystem for a complete experimental period of 10 weeks. The results demonstrated that the parameter of bite frequency was significantly different between the restricted and the control groups. There were also consistent differences observed between the groups for rumination time per day, rumination chews per bolus and frequency of cows standing or lying
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