Controlling crop disease contributes to both food security and climate change mitigation

Original article can be found at: http://www.tandfonline.com/ Copyright Taylor & FrancisGlobal food security is threatened by crop diseases that account for average yield losses of 16 per cent, with the greatest losses experienced by subsistence farmers in the developing world. Climate change is exacerbating the threats to food security in such areas, emphasizing the need to increase food production in northern European countries such as the UK. However, the crops must be grown in such a way as to minimize greenhouse gas (GHG) emissions associated with their production. As an example, it is estimated that production of UK winter oilseed rape is associated with GHG of 3300 kg CO2 eq. ha(-1) of crop and 834 kg CO2 eq. t(-1) of seed yield, with 79 per cent of the GHG associated with the use of nitrogen fertilizer. Furthermore, it is estimated that control of diseases by use of fungicides in this UK oilseed rape is associated with a decrease in GHG of 100 kg CO2 eq. t(-1) of seed. Winter oilseed rape cultivar disease resistance is associated with a decrease in GHG of 56 kg CO2 eq. t(-1), although this figure is an underestimate. These results demonstrate how disease control in arable crops can make a contribution to both climate change mitigation and sustainable arable crop production to ensure global food security.Peer reviewe

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

A comparision of GHG emissions from UK field crop production under selected arable systems with reference to disease control

Crop disease not only threatens global food security by reducing crop production at a time of growing demand, but also contributes to greenhouse gas (GHG) emissions by reducing efficiency of N fertiliser use and farm operations and by driving land use change. GHG emissions associated with adoption of reduced tillage, organic and integrated systems of field crop production across the UK and selected regions are compared with emissions from conventional arable farming to assess their potential for climate change mitigation. The reduced tillage system demonstrated a modest (<20%) reduction in emissions in all cases, although in practice it may not be suitable for all soils and it is likely to cause problems with control of diseases spread on crop debris. There were substantial increases in GHG emissions associated with the organic and integrated systems at national level, principally due to soil organic carbon losses from land use change. At a regional level the integrated system shows the potential to deliver significant emission reductions. These results indicate that the conventional crop production system, coupled to reduced tillage cultivation where appropriate, is generally the best for producing high yields to minimise greenhouse gas emissions and contribute to global food security, although there may be scope for use of the integrated system on a regional basis. The control of crop disease will continue to have an essential role in both maintaining productivity and decreasing GHG emissions.Peer reviewe

Disease control on UK winter oilseed rape contributes to climate change mitigation

The UK government has published plans to reduce UK agriculture‟s greenhouse gas (GHG) emissions. At the same time, the goal of food security requires an increase in arable crop yields. Foliar disease control measures such as fungicides have an important role in meeting both objectives. As an example, it is estimated that production of UK winter oilseed rape is associated with GHG of 3337 kg CO2 eq ha-1 of crop and 834 kg CO2 eq. t-1 of seed yield, with 79% of the GHG associated with the use of nitrogen fertiliser and only 0.3% of the GHG associated with fungicides, herbicides and insecticides. Furthermore, it is estimated that control of diseases by use of fungicides in this UK oilseed rape is associated with a decrease in GHG of 100 kg CO2 eq. t-1 of seed. Winter oilseed rape cultivar resistance against the pathogens P. brassicae and L. maculans is associated with decreases in GHG of 32 and 24 kg CO2 eq. t-1, respectively, although these figures are probably underestimates. Similar work has been done with winter wheat, winter barley and spring barley. Fungicide treatment of these four UK arable crops is estimated to have directly decreased UK GHG emissions by over 1.6 Mt CO2 eq. in 2009. These results demonstrate how disease control in arable crops can make an important contribution to climate change mitigation now. There is an urgent need to develop integrated strategies for disease control to sustain arable crop production and ensure global food security, whilst minimising greenhouse gas emissionsNon peer reviewedFinal Published versio