Search

Winter oilseed rape (OSR) is becoming an increasingly popular crop in rotations as it provides a cash crop and reduces the incidence of take-all fungal disease (caused by Gaeumannomyces graminis) in subsequent wheat production. The exact mechanism of this inhibition of fungal pathogens is not fully understood; however, the selective recruitment of bacterial groups with the ability to suppress pathogen growth and reproduction is thought to play a role. Here we examine the effect of tillage practice on the proliferation of microbes that possess the phlD gene involved in the production of the antifungal compound 2,4-diacetylphloroglucinol (2,4-DAPG), in the rhizospheres of both winter oilseed rape and winter wheat grown in rotation over a two-year period. The results showed that conservation strip tillage led to a significantly greater phlD gene copy number, both in the soil and in the roots, of oilseed rape and wheat crops, whereas crop rotation of oilseed rape and wheat did not increase the phlD gene copy number in winter wheat.

Abstract Increased precipitation during winter months in Western Europe is predicted from climate change. This is expected to increase the frequency of flooding events, with waterlogged conditions becoming more prevalent. A consequence of waterlogging is hypoxic conditions and dying back of roots, thereby negatively affecting plant nutrient uptake, growth, and development. Barley (Hordeum vulgare L.) forms lysigenous aerenchyma, which are air‐filled pockets within the root to facilitate O2 transport and support root respiration. Current methods for visualizing aerenchyma formation in roots are largely 2D and involve embedding a fixed root segment in resin, followed by destructive sectioning for microscopy. Here, we report the development of an X‐ray computed tomography (CT) acquisition and analytical method for spatio‐temporal identification and quantitation of aerenchyma in 2D and 3D in barley roots without the requirement for chemical fixation, resin embedding, followed by physical sectioning of the root. We demonstrated that the method we have developed can facilitate the identification and quantitation of aerenchyma in barley as early as 9 d post‐waterlogging. The method we have developed can be potentially applied to different plant species and has the potential to support the selection of breeding markers through X‐ray CT phenotyping of aerenchyma.

Nitrogen (N) application on winter oilseed rape (Brassica napus L.; WOSR) in the mild Atlantic climate of Ireland is based on a soil N Index system, which does not take into account any variations in crop N demand prior to the main spring dressing of N fertilizer. This study tests whether UK- canopy management (CM) principles for oilseed rape N fertilization are applicable for oilseed rape grown in Ireland. The tested principles included (i) final N uptake of unfertilized crops will be equivalent to the soil mineral N (SMN) and N in the crop measured at the end of winter, i.e., soil N uptake efficiency (SNUpE) = 1; and (ii) the (apparent) N fertilizer N uptake efficiency, (FNUpE) is 0.6 (60%). Three years of field trials were carried out from 2017/18 to 2019/20 on different sites based on a split-plot design. Three sowing dates (SD): mid-August (SD1), End-August (SD2) and mid-September (SD3) were set as main plots and five N application strategies namely, CM standard, CM higher yield, CM low N rate, Fix225 and zero-N were set at subplot level. Results from unfertilized plots demonstrated that the ratio of final crop N uptake at harvest to the combined post-winter SMN + crop N was 1.13 and 1.14 on the two early sowing dates but 1.68 for the latest sowing. Additionally, SMN was not systematically impacted by SD, except in site-year-2. Instead, crop N content in spring had the biggest influence when calculating soil N supply for the season. More mineralization occurred through the growing season resulting in SNUpE of above 100% on all SDs. This additional available N (AAN) was quantified as 11 kgN·ha−1 on average for SD1 and SD2 and 38.6 kgN·ha−1 for SD3. FNUpE values were calculated closest to the economical optimum N rate (Nopt) and were 0.534, 0.574 and 0.486, respectively for SD1, SD2 and SD3. The Nopts at each SD were 157 kgN·ha−1 (SD1), 148 kgN·ha−1 (SD2) and 175 kgN·ha−1 (SD3) and the respective yields at each Nopt were 4.93 t ha−1, 4.90 t·ha−1 and 4.34 t·ha−1. This study shows the UK–CM principles were applicable in the mild Irish climate; however, values of SNUpE and FNUpE differ from one site-year-SD to another. Mid-August to early September sowing dates produced higher post-winter crop N content due to SMN uptake, and this results in a lower Nopt than the later SD. Sowing later led to a higher Nopt due to a combination of lower post-winter N uptake and lower FNUpE, although the effect of these factors was partially offset by a greater AAN. Measurements of SNS post-winter, an estimate of N mineralization during the growing season, together with a consideration of the sowing date helped determine the scope for reduction in fertilizer while achieving high yield and high FNUpE. Among different N rate strategies, CM standard and CM high yield were closest to the Nopt for having lower N rates at the maximum economical yield point.

The natural co-occurrence of 42 mycotoxins was investigated in unprocessed oat grains grown in Ireland. The sample set included a total of 208 oat crops harvested during 2015–2016 and produced using conventional, organic, or gluten free farming systems. A range of different toxins was identified, including the major type A (neosolaniol, HT-2 and T-2 toxins, T-2 triol, and T-2-glucoside, co-occurring in 21 samples) and B trichothecenes (deoxynivalenol, nivalenol, and deoxynivalenol-3-glucoside), enniatins (B1, B, and A1, co-occurring in 12 samples), as well as beauvericin, alternariol, mycophenolic acid, and sterigmatocystin. The influences of sowing season, year, and production system were investigated, eventually indicating that the latter factor may have a higher impact than others on the production of certain mycotoxins in oats. The most frequently quantified compounds were HT-2 (51%) and T-2 (41%) toxins, with gluten free oats containing significantly lower concentrations of HT-2 compared to conventionally produced oats. Although the prevalence and concentrations of mycotoxin found in oat samples in this study should be substantially reduced by processing. However, as mycotoxin occurrence is clearly influenced by multiple factors, controlled field trials should be carried out to define optimal agronomic practices and mitigate mycotoxin production. Furthermore, this work highlights the need for regularly testing cereal-based foods with multi-residue analytical methods with wider specificities than the traditionally screened and regulated toxins, to generate knowledge on the occurrence of several mycotoxins that are, to date, rarely investigated.

Plant associated bacteria with plant growth promotion (PGP) properties have been proposed for use as environmentally friendly biofertilizers for sustainable agriculture; however, analysis of their efficacy in the field is often limited. In this study, greenhouse and field trials were carried out using individual endophytic Pseudomonas fluorescens strains, the well characterized rhizospheric P. fluorescens F113 and an endophytic microbial consortium of 10 different strains. These bacteria had been previously characterized with respect to their PGP properties in vitro and had been shown to harbor a range of traits associated with PGP including siderophore production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and inorganic phosphate solubilization. In greenhouse experiments individual strains tagged with gfp and Kmr were applied to Brassica napus as a seed coat and were shown to effectively colonize the rhizosphere and root of B. napus and in addition they demonstrated a significant increase in plant biomass compared with the non-inoculated control. In the field experiment, the bacteria (individual and consortium) were spray inoculated to winter oilseed rape B. napus var. Compass which was grown under standard North Western European agronomic conditions. Analysis of the data provides evidence that the application of the live bacterial biofertilizers can enhance aspects of crop development in B. napus at field scale. The field data demonstrated statistically significant increases in crop height, stem/leaf, and pod biomass, particularly, in the case of the consortium inoculated treatment. However, although seed and oil yield were increased in the field in response to inoculation, these data were not statistically significant under the experimental conditions tested. Future field trials will investigate the effectiveness of the inoculants under different agronomic conditions.

Gaining a greater understanding of the plant microbiota and its interactions with its host plant heralds a new era of scientific discovery in agriculture. Different agricultural management practices influence soil microbial populations by changing a soil’s physical, chemical and biological properties. However, the impact of these practices on the microbiota associated with economically important crops such as oilseed rape, are still understudied. In this work we investigated the impact of two contrasting crop establishment practices, conventional (plow based) and conservation (strip–tillage) systems, on the microbiota inhabiting different plant microhabitats, namely rhizosphere, root and shoot, of winter oilseed rape under Irish agronomic conditions. Illumina 16S rRNA gene sequence profiling showed that the plant associated microhabitats (root and shoot), are dominated by members of the bacterial phyla Proteobacteria, Actinobacteria and Bacteroidetes. The root and shoot associated bacterial communities displayed markedly distinct profiles as a result of tillage practices. We observed a very limited ‘rhizosphere effect’ in the root zone of WOSR, i.e., there was little or no increase in bacterial community richness and abundance in the WOSR rhizosphere compared to the bulk soil. The two tillage systems investigated did not appear to lead to any major long term differences on the bulk soil or rhizosphere bacterial communities. Our data suggests that the WOSR root and shoot microbiota can be impacted by management practices and is an important mechanism that could allow us to understand how plants respond to different management practices and environments.

This paper addresses the role of governments, industry, academics, and non-governmental organizations in Food Fraud prevention. Before providing strategic concepts for governments and authorities, definitions of Food Fraud are reviewed and discussed. Next there is a review of Food Fraud activities by the Global Food Safety Initiative (GFSI), the Elliott Review in the United Kingdom, the European Commission resolution on Food Fraud, and the US Food Safety Modernization Act including the Preventative Controls Rule. Two key concepts for governments or a company are: (1) formally, and specifically, mention food fraud as a food issue and (2) create an enterprise-wide Food Fraud prevention plan. The research includes a case study of the implementation of the concepts by a state or provincial agency. This analysis provides a foundation to review the role of science and technology in detection, deterrence and then contributing to prevention.