2,167 research outputs found

    Sustainable production of organic wheat

    Get PDF
    The aim of the project is to use an ecological approach to analyse the interactions of a range of key agronomic variables in organic wheat production (wheat genotype, spatial arrangement of seed, seed density and wheat/white clover bi-cropping) to determine an optimal approach to improved and stabilised production. The fi rst set of data revealed that seedling competition was infl uenced by seed rate and drilling arrangement. Furthermore, the variety Hereward had increased emergence and establishment to Aristos. An interaction exists between wheat variety, seed rate and drilling arrangement on the level of canopy cover at different developmental stages – these factors are important for the suppression of weeds. The input of farmers in the selection of trial variables ensures results have a direct application to the industry. The results of yield and quality at harvest will provide further insights into the interaction of agronomic variables

    Evolutionary breeding of healthy wheat: from plot to farm

    Get PDF
    Genetically diverse Composite Cross Populations (CCPs) may be useful in environmentally variable low-input systems as an alternative to pure line varieties. They are formed by hybridising lines with diverse evolutionary origins, bulking the F1 progeny, and allowing natural selection of the progeny in successive crop environments. CCPs derived from 10 high yielding parents (YCCPs), 12 high quality parents (QCCPs), or all 22 parents (YQCCPs), were grown at four sites (2 organic, 2 conventional) in the UK; they are currently (2006) in F5. The YCCPs out yielded the QCCPs, which had better quality characteristics. Although the CCPs performed within the range of the parents, the values obtained were often better than the mean of the parents. Some population samples are now being grown on farms and other sites in England, France, Germany and Hungary

    The identification and production of varieties that increase the value of oats as a profitable component of organic production

    Get PDF
    Two experiments, one comprising husked, and the other naked, oats were established at Wakelyns Agroforestry, Suffolk in October 2004 to determine traits and varieties of oats suited to organic systems, and whether growing variety mixtures conferred any advantage. Unselected F2 breeding lines were also included for selection. Husked varieties had relatively higher yields; this may have been partly the result of poor establishment in the naked varieties. Variety height was found to be an important characteristic; tall oat varieties out-yielded the dwarfs. Two of the three variety mixtures containing the naked oat variety Expression yielded 8 and 9 % higher than the average of the component varieties. The data will be verified in the second year of replicated trials (2005/06), which will include the best performing husked and naked varieties, and a mixture of superior IGER-bred F2 breeding lines

    Optical studies of two LMC X-ray transients : RX J0544.1-7100 and RX J0520.5-6932

    Full text link
    We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and SAAO, together with results from the OGLE data base, are presented. In addition, X-ray data from the RXTE all-sky monitor are investigated for long term periodicities. A strong suggestion for a binary period of 24.4d is seen in RX J0520.5-6932 from the OGLE data.Comment: 6 pages, 7 figure

    Framework for local government to implement integrated water resource management linked to water service delivery

    Get PDF
    The Water Services Act (No. 8 of 1997) of South Africa states that water service delivery is the responsibility of local government as Water Services Authorities. The principal legal responsibility is to complete a Water Services Development Plan (WSDP) every 5 years with annual review. The WSDP encapsulates all the responsibilities and tasks required in water service delivery. However, it does not spell out local government’s role in water resource protection or its responsibilities as far as integrated water resource management is concerned. It is well known in South Africa that there is a challenging level of inadequate capacity in technical and administrative skills in local government to adequately fulfil water service delivery. This paper highlights the consequences of this incapacity for municipalities and their difficulties in fulfilling their responsibilities as service providers. A framework is provided within which improvements can be brought about, with guidance on how to engage in the practice of integrated water resource management (IWRM) in the context of the legal framework for water services. The additional tasks and changes required to practise IWRM are set in the context of the WSDP. The framework provides a guide for a municipality to first accomplish an adequate WSDP, and then to gradually implement IWRM. A discussion on the skills needed to accomplish, firstly, a comprehensive WSDP, and secondly, IWRM, is included

    Effects of Sulfates in Water on Performance of Steers Grazing Rangeland

    Get PDF
    Surface and subsurface water in South Dakota often contains high concentrations of total dissolved solids (TDS) and sulfates, which, in severe cases, can cause livestock deaths. Data from our laboratory have demonstrated that sulfate concentrations of 3,000 ppm in water consumed by steers in dry-lot decreased ADG, feed intake, and water consumption. Little information is available on the effects of water sulfate concentrations on grazing livestock. This study evaluated the effects of water quality and two vegetation communities on the performance of steers grazing rangeland. Eight native pastures at the SDSU Cottonwood Research Station were used. Four pastures were dominated by warm-season shortgrasses (SG) and four by cool-season midgrasses (MG). Yearling steers (105/year) were allotted to pastures in 2001 and in 2002 to attain a moderate stocking rate of 0.50 AUM/acre during a 4-month grazing season. In 2002, cattle were removed after two months due to drought, resulting in a stocking rate of 0.25 AUM/acre. Number of cattle per pasture varied from 7 to 30, depending on pasture size. Cattle in two of the SG and two of the MG pastures received high sulfate water (HS, 2001: average = 3,947 ppm sulfates; 2002: average = 4,654 ppm sulfates) with low sulfate water (LS, 2001: average = 404 ppm sulfates; 2002: average = 441 ppm sulfates) provided in the remaining pastures. Average daily gain was greater for the LS steers than HS steers in 2001 (P = 0.003; 1.85 and 1.65 lb/d, respectively) and in 2002 (P = 0.001; 2.43 and 1.79 lb/d, respectively). An interaction between sulfate concentration in water and vegetation community in 2002 (P = 0.078) resulted from similar ADG for steers on SG (1.83 lb/d) and MG (1.74 lb/d) pastures for HS water, but greater ADG for steers on MG (2.54 lb/d) than SG (2.32 lb/d) pastures for LS water. During the two-year study, only one steer had health problems related to sulfur, with no deaths. Our study showed water with sulfate concentrations of 3,947 ppm and greater reduced ADG of grazing steers, and that the response was influenced by vegetation

    Developing a partcipatory approach to seed production and varietal selection

    Get PDF
    The performance of UK winter wheat varieties was tested under organic conditions involving farmer participation. Three breadmaking varieties (Hereward, Solstice and Xi19) and their mixture (1:1:1) were grown at 19 UK farms in 2003/04 and 2004/05. The variability of productivity on organic farms was illustrated with more variation among farm sites than among varieties. Seed health was generally high over all sites. Although the trials were successful, more time was needed at project initiation to improve farmer involvement. Some farmers expected more researcher visits, and were reticent about assessing the trials themselves. In contrast, some participants valued the variety performance data on their farms particularly when related to that of other growers. The balance between the goals of the researchers relative to the farmers needs to be defined at project initiation

    New developments in the methodology available for the assessment of topical corticosteroid-induced skin blanching

    Get PDF
    Since the publication of the previous edition of this book there have been considerable developments and controversy in the field of topical corticosteroid bioequivalence assessment. There has been considerable discussion in the literature concerning the use of the Minolta chromameter for the measurement of corticosteroid-induced skin blanching, as it is believed this instrument would produce more objective results than the visual grading procedure. These efforts culminated in the release of a guidance document from the Food and Drug Administration (FDA) detailing the procedures to be followed for the determination of topical corticosteroid bioequivalence using the chromameter. Since the promulgation of this document there have been challenges on the validity and scientific merit of the documented procedures, and recently the FDA itself conceded that it may be necessary to redefine some of the protocol evaluations. This chapter attempts to redefine the current standing of the two methods of response assessment

    The human skin-blanching assay for comparing topical corticosteroid availability

    Get PDF
    The human skin blanching assay remains in widespread use as a reliable, qualitative, comparative indicator of topical corticosteroid availability and potency. The experimental refinements promulgated by certain researchers in this field have yielded a versatile bioassay for the accurate assessment of new drugs or delivery vehicles. With the increasing appearance of generic topical corticosteroid formulations which compete with trade-name equivalents, the vital importance of this assay in regulatory affairs and assessing bioequivalence has been re-emphasized. It is stressed that if the blanching assay is to be used in this sphere, then multiple-reading trials must be conducted; important registration or clinical decisions cannot be made with any validity from short-term assessments
    • …
    corecore