Our research is designed to help UK farmers control soil pests which damage crop production cheaply and effectively at the same time as reducing dependence on conventional pesticides which might harm the environment. The most damaging of these soil pests are microscopic nematode worms. There are different species of nematodes: some attack potato plants whilst others can infect a range of plants, including carrots and soft fruit. The most prevalent economically important species of nematode, and so the one that has the highest economic impact on UK farmers, infects the roots of potato plants and is consequently termed potato cyst nematode (PCN). There are disproportional impacts on our potato industry because of a higher incidence of PCN in the UK than in most of Europe. EU legislation has resulted in the recent loss of two major chemicals used to control nematode pests, termed nematicides, in response to the environmental concerns their use raised and plans to amend the legislation regulating pesticide use still further are likely to remove the three remaining nematicides, possibly quite suddenly. This is causing major concern to the British potato industry because it is doubtful if new pesticides, which are effective but also meet appropriate environmental safety standards, can be developed in time to replace the pesticides being phased out. One alternative control method that could be adopted in the limited timeframe available to UK potato growers is a strategy known as biofumigation, which suppresses pests by incorporating mustards and other types of plants into soil. Potato Council Ltd (which safeguards the interests of the UK potato growing industry) and the Horticultural Development Company (which promotes the UK horticultural sector), in conjunction with potato businesses, have now committed to support research to understand exactly how biofumigation works and how the potential of this technique can be exploited most effectively under field conditions. Our preliminary work has characterised a number of different plant species that produce natural chemicals which detrimentally affect PCN. We have shown that biofumigation can be used to stop the eggs of PCN from hatching into worms which subsequently attack potato plants. We have identified different types of mustard plant that could be used in biofumigation because of the range of natural anti-nematode chemicals they produce. However, inconsistencies in the effectiveness of these plants and a lack of detailed data on how best to deploy biofumigation under a range of agronomic situations prevent the widespread uptake of this sustainable pest control technique. This project will address this knowledge gap by elucidating the fundamental biochemical and metabolic processes underpinning effective biofumigation. It will characterise the profiles of the active chemical compounds, called glucosinolates, of different biofumigant mustards and determine how these vary with plant development stage and environmental factors. It will identify novel active compounds potentially effective against pests but not, as yet, evaluated in biofumigant field trials. We will analyse the effects of biofumigant plants on a range of pests both in glasshouse studies and in multiple field trials. We will use a novel plant growth technique that makes soil appear transparent allowing us to observe the effects of biofumigation on some of the nematode species for the first time. It must be shown that biofumigation does not adversely affect UK soils before the approach can be endorsed by the Potato Council, DEFRA, EU or certifiers of organic produce. We will therefore analyse the impact of biofumigant crops on beneficial organisms in the soil when deployed in the field. Outputs of the research will allow optimal deployment of biofumigation strategies for maximum efficiency over a range of field conditions, providing a sustainable pest control option for both conventional and organic farmers.

Agriculture is a major cause of greenhouse gas (GHG) emissions, pollution and biodiversity loss globally and in the UK. Achieving sustainable ('green') growth of agricultural production to feed 10 billion people by 2050 whilst reducing environmental impacts is one of the greatest challenges facing humanity. Changing our diets and reducing food waste are part of the solution. However, as recognised in the UK government's Clean Growth Grand Challenge, significant green growth in the agri-food sector is also necessary to meet this demand without compromising other targets, in particular that of neutrality in carbon emissions by 2050. The GREEN AG programme will build a long-term, strategic research and innovation infrastructure to develop new UK farming systems which will produce sufficient food whilst reducing emissions and pollution, protecting biodiversity, and enhancing soil health. We call this 'net zero+' as it will balance net zero emissions aims with wider environmental concerns. These solutions will be required at scale if the UK is to meet emission reduction targets, and avoid the unintended consequences of emissions being offshored by increased food imports, or causing damage to valuable ecosystems in the UK. GREEN AG will engage and unite the science community with industry, policy, farmer and NGO stakeholders. We will identify farm management practices with potential to reduce emissions and/or capture carbon without major impacts on food production or other environmental outcomes. We will undertake detailed, integrated measurements of these practices on both experiments and on a network of instrumented study farms (Living Farm Labs). We will use models to define pathways to achieving net zero+ arable and livestock farm systems that minimise trade-offs with production and the environment. Finally, we will use cutting edge data science to provide data, models and tools to enable the transition to net zero+ agriculture. Achieving the ambition of clean, green and net-zero agriculture will require strategic, cross-disciplinary and long-term research - a so-called national capability. This will bring together directed teams from NERC and BBSRC centres - UK Centre for Ecology & Hydrology, Rothamsted Research, National Centre for Earth Observation, British Geological Survey and Plymouth Marine Laboratory. This partnership will bring together complementary expertise in ground and earth observation, sensor networks, measurement of GHG emissions from soils, groundwater and estuaries, pollution, biodiversity, crop and livestock production, data science and modelling from field to national scales, covering terrestrial, freshwater and coastal zones. Our environmental research will complement work on other aspects of the farming system that might support net zero+, including crop breeding, animal husbandry and diet, soil science, and crop nutrition and protection. The GREEN AG national capability will provide the following outcomes for the UK science community and other stakeholders: - New knowledge underpinning effective agri-environmental policies to achieve net zero emissions by 2050; - New funding opportunities levered from the GREEN AG research and innovation infrastructure which comprise a national digital farmland observatory, instrumented study farms, experiments, data and models; - More effective implementation of net zero+ polices and practice through stakeholder engagement and co-design, and through the provision of new decision support tools; - Opportunities for UK researchers and agri-businesses to export this green growth knowledge, technology and innovations to overseas markets.

Nitrogen fertiliser is essential to sustain wheat yields but is also an important determinant of grain quality. This is because nitrogen is required for the synthesis of grain proteins, with the gluten proteins forming the major grain protein fraction. About 40% of the wheat produced in the UK is used for food production, particularly for making bread and other baked products. Wheat is also widely used as a functional ingredient in many processed foods, while bread wheat and imported durum wheats are used to make noodles and pasta, respectively. The gluten proteins are essential for these uses, providing visco-elastic properties to dough. Consequently, the content and quality of the grain proteins affect the processing quality, with a minimum of 13% being specified for the Chorleywood Breadmaking Process (CBP) which is used for over 80% of the "factory produced" bread in the UK. The requirement of nitrogen to produce wheat for bread making is also above the optimum required for yield, and farmers may apply up to 50 kg N/Ha above the yield optimum to achieve 13% protein (2.28% N). This is costly with nitrogen fertiliser contributing significantly to crop production, and may also contribute to a greater "nitrogen footprint" in the farmed environment. It may be possible to reduce the requirement for breadmaking wheats, to a limited extent, by optimising the efficiency of nitrogen uptake and use within the wheat plant. However, this will only have limited benefits and a more viable long-term solution is to develop new types of wheat and processing systems which will allow the use of lower protein contents for bread making. We will therefore identify types of wheat which have good and stable breadmaking quality at low grain protein. Genetic analyses of the trait will provide molecular markers to assist wheat breeders while studies of underpinning mechanisms will allow new selection procedures to be used to identify germplasm and select for quality in breeding programmes. We will also work with millers and bakers to establish optimum conditions for processing of wheats with lower protein contents.

Our project is designed to facilitate the practical development of plant defence activators, such as cis-jasmone, as novel crop protection treatments for use against aphids. Earlier research has shown that cis-jasmone treatment can significantly reduce aphid infestations in the field and that treated plants become repellent to aphids while also becoming more attractive to natural enemies of pests. Plant defence activators have the advantage of having a non-toxic mode of action. They work by switching on (inducing) defence in plants and could provide new, environmentally friendly crop protection options. Farmers urgently need new options as conventional pesticide use is increasingly restricted by changes in legislation and compromised by evolution of resistance. Plant defence activators are: * environmentally friendly * work with not against natural enemies of pests * provide new interventions farmers can use against pests * form part of integrated pest management (IPM) * can be used against insecticide resistant pests Here, we will make the next steps towards commercialisation of plant defence activator treatments. We have discussed with Agrii, a leading UK agronomy company, the research that would be needed. Wheat is their preferred crop for initial trials due to the large area it is grown in and also because our earlier field trials have already shown cis-jasmone can reduce aphid populations in wheat. Agrii have other potential plant defence activators (AGRII101, AGRII202) they would like to test alongside cis-jasmone in order to compare performance. Our project will therefore conduct field trials comparing different plant defence activator treatments with each other as well as with untreated control plots and plots treated with a standard pyrethroid insecticide. We will test the performance of plant activators with different wheat varieties because different varieties can have different capacity for inducing defence. Having tested efficacy under realistic conditions we will then explore with regulatory authorities how to obtain regulatory approval for for plant activators. The benefits listed above mean a strong case can be made for regulatory approval and we will include dialogue with regulators as a project objective.

My research concerns a fungus, Zymoseptoria tritici (Zt), which attacks wheat plants, causing a disease known as Septoria tritici blotch (STB). STB costs the UK around £300 Million per year in lost wheat yields and in the cost of the fungicide used on the crops. Worse, the fungus is developing resistance to the fungicides available to treat it. This means that we need new methods to control the infection. To develop new ways to control Zt, it is necessary to gain a full understanding of the ways in which the fungus interacts with the wheat plant, and how that interaction can be affected by environmental conditions. In previous work, I showed that some isolates of Zt can grow on the leaf surface for around ten days before invading. The amount and duration of leaf surface growth varies between fungal isolates, and also when the same isolate infects different wheat varieties. Most plant pathogenic fungi, by contrast, can't obtain enough nutrients on the leaf surface to survive for more than 24 h. My FLF research programme aimed to determine the importance of this leaf surface growth phase for Zt, whether it is related to disease severity, and how inter-isolate differences in epiphytic growth are encoded in the genome. To understand fungal survival on the leaf surface, my project also aimed to determine what nutrients the fungus is using during this period, and how it interacts with other leaf surface microbes. My team and I are currently describing the epiphytic phenotypes of over 60 GFP-tagged isolates across a panel of wheat cultivars with varying degrees of resistance. We are linking these data to the genotypes and metabolite uptake profiles of the isolates to build a complete picture of the mechanisms underpinning surface survival. We have identified previously undescribed behaviours in Zt, including the ability to form biofilms. We have also carried out extensive field sampling, and are studying the interactions between Zt and other leaf surface microbes. During the next phase of the project, I will focus on three objectives: First, I will create reporter strains to visualise differences in nutrient uptake between isolates with different epiphytic phenotypes. The genes used to create these reporter strains will be based on the information gathered in the project so far, concerning the genetic and metabolic differences underlying epiphytic phenotypes. The reporters will allow us to visualise, in real time, how different isolates respond to changes in leaf surface nutrient availability due to, for e.g., fertilisation or pollen deposition. I will use this information to propose changes in fungicide/fertiliser application regimes that will optimise disease control. Secondly, I have shown that Zt can form biofilms, which have greater resistance to stresses such as drying, high temperature, and fungicides than do non-biofilm cells. I will determine whether and when biofilm formation occurs under field conditions and whether biofilms alter the outcome of fungicide treatment or survival of the pathogen during, for example, a heatwave. This work will help to develop weather-sensitive fungicide regimes and maximise fungicide efficacy, thus minimising the risk of further fungicide resistance emerging. Thirdly, I will explore options arising from our work to develop biocontrol of Zt. I will search our field-collected epiphyte library for organisms linked to increased/decreased disease in our related field data. I will then conduct experiments to see whether those linked to low disease are viable as biocontrol agents or, conversely, whether those linked to increased disease can be controlled, for example by working with Exeter's Citizen Phage Library to find phages that infect them. These three objectives will provide significant increases in our understanding of Zt infection biology and ecology alongside novel disease control mechanisms, which can then be tested in collaboration with our agricultural partners.