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控制土壤害虫，这些害虫廉价而有效地损害作物生产，同时减少对可能损害环境的传统杀虫剂的依赖。这些土壤害虫中危害最大的是微小的线虫。有不同种类的线虫：一些攻击土豆植物，而另一些可以感染一系列植物，包括胡萝卜和软果。马铃薯孢囊线虫是一种最常见的重要经济线虫，也是对英国农民经济影响最大的一种，它侵染马铃薯植株的根部，因此被称为马铃薯孢囊线虫(PCN)。由于PCN在英国的发病率高于欧洲大部分地区，因此对我们的马铃薯产业产生了不成比例的影响。欧盟立法最近失去了两种用于控制线虫害虫的主要化学物质，被称为线虫杀虫剂，以回应它们的使用引发的环境问题，而且进一步修改规范农药使用的立法的计划可能会取消剩余的三种线虫杀虫剂，可能会非常突然。这引起了英国土豆行业的主要担忧，因为人们怀疑是否能及时开发出既有效又符合适当环境安全标准的新杀虫剂，以取代正在逐步淘汰的杀虫剂。英国土豆种植者可以在有限的时间内采用的一种替代控制方法是一种名为生物熏蒸的策略，它通过在土壤中加入芥菜和其他类型的植物来抑制害虫。马铃薯委员会有限公司(保护英国马铃薯种植行业的利益)和园艺发展公司(促进英国园艺行业)现在与马铃薯企业一起致力于支持研究，以确切地了解生物熏蒸是如何起作用的，以及如何在田间条件下最有效地利用这项技术的潜力。我们的初步工作确定了一些不同的植物物种的特征，这些植物产生有害影响PCN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，然后蠕虫攻击马铃薯植株。我们已经确定了不同类型的芥末植物可以用于生物熏蒸，因为它们产生了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情况下最好地部署生物熏蒸的详细数据，阻碍了这种可持续虫害控制技术的广泛采用。该项目将通过阐明支持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蒸剂芥末的活性化合物硫代葡萄糖酸盐的特征，并确定这些化合物如何随植物发育阶段和环境因素而变化。它将确定可能对害虫有效的新活性化合物，但尚未在生物熏蒸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，使我们第一次观察到生物熏蒸对一些线虫物种的影响。在土豆委员会、DEFRA、欧盟或有机农产品认证机构认可这种方法之前，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种植时对土壤中有益生物的影响。这项研究的成果将使生物熏蒸战略得到最佳部署，在一系列田间条件下实现最大效率，为传统农民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.