Establishing biofumigation as a sustainable pesticide replacement for control of soil-borne pests and pathogens in potato and horticultural crops.

我们的研究旨在帮助英国农民廉价有效地控制破坏作物生产的土壤害虫，同时减少对可能危害环境的传统农药的依赖。这些土壤害虫中最具破坏性的是微小的线虫。线虫有不同的种类：一些攻击马铃薯植物，而另一些可以感染一系列植物，包括胡萝卜和软果。最普遍的经济上重要的线虫物种，因此对英国农民有最大的经济影响，感染马铃薯植物的根，因此被称为马铃薯囊肿线虫（PCN）。由于PCN在英国的发病率高于欧洲大多数国家，因此对我们的马铃薯产业产生了不成比例的影响。欧盟立法导致最近失去了两种用于控制线虫害虫的主要化学品，称为杀线虫剂，以回应其使用引起的环境问题，并计划进一步修订管制农药使用的立法，可能会突然取消剩余的三种杀线虫剂。这引起了英国马铃薯行业的极大关注，因为人们怀疑是否能够及时开发出有效且符合适当环境安全标准的新农药来取代正在逐步淘汰的农药。在有限的时间内，英国马铃薯种植者可以采用一种替代控制方法，即生物熏蒸，通过将芥菜和其他类型的植物结合到土壤中来抑制害虫。马铃薯委员会有限公司（保护英国马铃薯种植业的利益）和园艺发展公司（促进英国园艺部门的发展）与马铃薯企业一起，现在承诺支持研究，以了解生物熏蒸的工作原理，以及如何在田间条件下最有效地利用这种技术的潜力。我们的初步工作已经描述了许多不同的植物物种，它们产生对PCN有害的天然化学物质。我们已经证明，生物熏蒸可以用来阻止PCN的卵孵化成蠕虫，随后攻击马铃薯植物。我们已经确定了不同类型的芥菜植物，它们可以用于生物熏蒸，因为它们产生一系列天然的抗线虫化学物质。然而，这些植物的有效性不一致，以及缺乏关于如何在一系列农艺条件下最佳部署生物熏蒸的详细数据，阻碍了这种可持续虫害防治技术的广泛采用。该项目将通过阐明支撑有效生物熏蒸的基本生化和代谢过程来解决这一知识差距。它将描述不同生物熏染芥菜中被称为硫代葡萄糖苷的活性化合物的特征，并确定这些化合物如何随着植物发育阶段和环境因素而变化。它将鉴定出可能对害虫有效的新型活性化合物，但尚未在生物熏蒸剂的田间试验中进行评估。我们将在温室研究和多个田间试验中分析生物熏蒸植物对一系列害虫的影响。我们将使用一种新的植物生长技术，使土壤看起来透明，使我们能够首次观察生物熏蒸对一些线虫物种的影响。在马铃薯委员会、DEFRA、欧盟或有机农产品认证机构认可该方法之前，必须证明生物熏蒸不会对英国土壤产生不利影响。因此，我们将分析生物熏蒸作物在田间施用时对土壤中有益生物的影响。该研究的产出将允许在各种田间条件下最佳地部署生物熏蒸策略，以实现最大效率，为传统和有机农民提供可持续的虫害防治选择。

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.