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 emissions