Prevalence of QoI resistance and mtDNA diversity in the Irish Zymoseptoria tritici population

peer-reviewedThe emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain

Distribution and incidence of viruses in Irish seed potato crops

peer-reviewedVirus diseases are of key importance in potato production and in particular for the production of disease-free potato seed. However, there is little known about the frequency and distribution of potato virus diseases in Ireland. Despite a large number of samples being tested each year, the data has never been collated either within or across years. Information from all known potato virus testing carried out in the years 2006–2012 by the Department of Agriculture Food and Marine was collated to give an indication of the distribution and incidence of potato virus in Ireland. It was found that there was significant variation between regions, varieties, years and seed classes. A definition of daily weather data suitable for aphid flight was developed, which accounted for a significant proportion of the variation in virus incidence between years. This use of weather data to predict virus risk could be developed to form the basis of an integrated pest management approach for aphid control in Irish potato crops

Evaluation of the ’Irish Rules’: The Potato Late Blight Forecasting Model and Its Operational Use in the Republic of Ireland

peer-reviewedPotato late blight caused by Phytophthora infestans is one of the most important plant diseases known, requiring high pesticide inputs to prevent disease occurrence. The disease development is highly dependent on weather conditions, and as such, several forecasting schemes have been developed worldwide which seek to reduce the inputs required to control the disease. The Irish Rules, developed in the 1950s and calibrated to accommodate the meteorological network, the characteristics of potato production and the P. infestans population at the time, is still operationally utilized by the national meteorological agency, Met Éireann. However, numerous changes in the composition and dynamics of the pathosystem and the risks of production/economic consequences associated with potato late blight outbreaks have occurred since the inception of the Irish Rules model. Additionally, model and decision thresholds appear to have been selected ad hoc and without a clear criteria. We developed a systematic methodology to evaluate the model using the empirical receiver operating curve (ROC) analysis and the response surface methodology for the interpretation of the results. The methodology, written in the R language, is provided as an open, accessible and reproducible platform to facilitate the ongoing seasonal re-evaluation of the Irish Rules and corresponding decision thresholds. Following this initial analysis, based on the available data, we recommend the reduction of the thresholds for relative humidity and an initial period duration from 90% and 12 h to 88% and 10 h, respectively. Contrary to recent reports, we found that the risk of blight epidemics remains low at temperatures below 12 °C. With the availability of more comprehensive outbreak data and with greater insight into the founder population to confirm our findings as robust, the temperature threshold in the model could potentially be increased from 10 °C to 12 °C, providing more opportunities for reductions of pesticide usage. We propose a dynamic operational decision threshold between four and 11 effective blight hours (EBH) set according to frequency of the disease outbreaks in the region of interest. Although the risk estimation according to the new model calibrations is higher, estimated chemical inputs, on average, are lower than the usual grower’s practice. Importantly, the research outlined here provides a robust and reproducible methodological approach to evaluate a semi-empirical plant disease forecasting model

Potatoes in Ireland: Sixty years of potato research and development, market evolution and perspectives on future challenges

peer-reviewedPotato is often considered synonymous with Ireland, due to the great Irish famine in 1845, and remains the most important primary food crop in Ireland. Over the last 60 yr, the area of potatoes has reduced from 86,000 ha to 9,000 ha. This trend has occurred in most developed countries but in Ireland it is due to decreasing consumption, increasing yield, decline in seed production and potatoes no longer being use for animal feed. Significant specialisation occurred in the industry during the 1990s, with improvements in agronomy, on farm investment in storage and field equipment, consolidation of packing facilities, and a significant shift in cultivar choice, with Rooster becoming the dominant cultivar. These developments led to an increase in yield from 20 t/ha in the mid-1980s to over 40 t/ha today. Potato research in Ireland has focused on breeding, pathology and agronomy, while there have been significant changes in how knowledge is communicated to growers and the industry in this period. The industry faces many challenges in the future, largely framed by climate change, the need to reduce fertiliser and plant protection products as part of the EU Farm to Fork Strategy and industry size constraints. New superior potato varieties and novel breeding techniques will have potential to help address many challenges in combination with integrated pest management principles. Multi-actor approaches will be necessary to address all challenges but particularly to aid the industry grow and exploit emerging opportunities

Identifying the drivers and constraints to adoption of IPM amongst arable farmers in UK and Ireland.

Publication history: Accepted - 2 May 2021; Published online - 15 May 2021.BACKGROUND Arable crops in temperate climatic regions such as the UK and Ireland are subject to a multitude of pests (weeds, diseases and vertebrate/invertebrate pests) that can negatively impact productivity if not properly managed. Integrated pest management (IPM) is widely promoted as a sustainable approach to pest management, yet there are few recent studies assessing adoption levels and factors influencing this in arable cropping systems in the UK and Ireland. This study used an extensive farmer survey to address both these issues. RESULTS Adoption levels of various IPM practices varied across the sample depending on a range of factors relating to both farm and farmer characteristics. Positive relationships were observed between IPM adoption and farmed area, and familiarity with IPM. Choice of pest control information sources was also found to be influential on farmer familiarity with IPM, with those who were proactive in seeking information from impartial sources being more engaged and reporting higher levels of adoption. CONCLUSION Policies that encourage farmers to greater levels of engagement with their pest management issues and more proactive information seeking, such as through advisory professionals, more experienced peers through crop walks, open days and discussion groups should be strongly encouraged.We acknowledge the financial and logistical support of the: Scottish Government Strategic Research Programme; Rural Business Research (England); Department of Agriculture, Food and the Marine (Ireland) (RSF 14/S/879); and the Department of Agriculture, Environment and Rural Affairs (Northern Ireland) in enabling the study reported here

Identifying the drivers and constraints to adoption of IPM amongst arable farmers in the UK and Ireland

BACKGROUND: Arable crops in temperate climatic regions such as the UK and Ireland are subject to multitude of pests (weeds, diseases and vertebrate/invertebrate pests) that can negatively impact productivity if not properly managed. Integrated pest management (IPM) is widely promoted as a sustainable approach to pest management, yet there are few recent studies assessing adoption levels and factors influencing this in arable cropping systems in the UK and Ireland. This study used an extensive farmer survey to address both these issues. RESULTS: Adoption levels of various IPM practices varied across the sample depending on a range of factors relating to both farm and farmer characteristics. Positive relationships were observed between IPM adoption and farmed area, and familiarity with IPM. Choice of pest control information sources was also found to be influential on farmer familiarity with IPM, with those who were proactive in seeking information from impartial sources being more engaged and reporting higher levels of adoption. CONCLUSION: Policies which encourage farmers to greater levels of engagement with their pest management issues and more proactive information seeking, such as through advisory professionals, more experienced peers through crop walks, open days and discussion groups should be strongly encouraged

Blumeria graminis f. sp. avenae

Blumeria graminis f. sp. avenae (Bga), the causal agent of powdery mildew disease on oats, is one of the most important diseases of oat production. The main control strategies include the use of fungicides and resistant cultivars. However, with the overuse of chemical controls and a dependency on a limited number of resistance genes, this pathogen is becoming more difficult to control and eradicate from the crop. To date, only 12 genes that confer resistance to Bga have been catalogued in oats, and only half of these are deployed in commercially available oat cultivars. Because of this, there is a constant need to understand the mechanisms underlying oat resistance and a demand for new durable forms of resistance