Development and delivery of knowledge transfer activities on current best practice for Oomycete root rot detection and control


CP 128 - Development and delivery of knowledge transfer activities on current best practice for Oomycete root rot detection and control

Start Date: 
Completion Date: 
Project Leader: 
Dr Tim Pettitt, University of Worcester
CP 128

Industry representative: Russ Woodcock, Bordon Hill Nurseries Ltd

AHDB Horticulture project cost: £24,848


The Problem:

This project will produce a comprehensive and up-to-date guide and critique in the form of a series of factsheets for UK Growers on currently available information, approaches and techniques for the detection and effective control/management of Oomycete root- and stem-rot pathogens.  The information in the guide will also be presented in a series of grower workshops.  Both the workshops and the guide will explore how currently available techniques and materials can be integrated to give the most effective control options across the different sectors of UK Horticulture, and the importance of using appropriate questioning, detection and diagnostic methods in monitoring and maintaining effective disease management.  Innovative disease management approaches are currently being successfully deployed by forward-looking growers despite not being fully understood or optimised.  These will be considered in this context together with more established methodologies, whilst the gaps in our current knowledge/capabilities, and the potential for future developments and refinements will be identified.


Aims and objectives:


To provide and disseminate to the UK Horticultural Industry, using factsheets, grower workshops and other media, a comprehensive update on the techniques and materials currently available for monitoring, management and control of Oomycete root- and stem-rot pathogens, to help inform and guide current best practice and indicate possibilities for future development.  This project will be complementary to the HDC desk study CP126 and other HDC outputs and will focus on:


  1. Understanding the organisms – Oomycetes, what are they?  What makes them different? How is this important?


  1. Symptoms and diseases – what to look for and early signs of disease problems, potential losses and the risks of disease.


  1. Diagnostics and Detection – what is available and from where?  What is appropriate?  The most useful questions to ask and what the answers might mean.


  1. Management/Control
  • Inoculum – what is it?  How to reduce it on site.  Hygiene.  ‘Zero tolerance’ of puddles.  Disinfection.  Cleaning roofs and gutters.  Foot dips for sensitive areas.  Use of barriers.  Water treatments.
  • Environment – factors that can be altered to reduce disease.  Drainage. Cultivations and mulches.  Air flow, Temperatures, RH and irrigation.
  • Treatments – Chemicals – fungicides (should be Oomyceticides?), disinfectants.  Bio-fungicides.  Biological Control Agents, Elicitors and Plant Growth Stimulants/Strengtheners.  Predictive deployment of control systems for optimal effect.
  • Natural Disease Suppression – what is it?  What is known?  How it can break down.  Its place in integrated systems (e.g. Iris bed systems) or the encouragement/protection of myco-parasitic species commonly found in horticultural soils (e.g. Pythium oligandrum).
  • Integrated control systems – How the various factors, cultural activities and treatments outlined above can be put together with an understanding of the pathogens and their detection/monitoring to provide good integrated control systems.



  1. In conjunction with HDC Desk Study (CP126), collect and collate technical descriptions, and where useful, take photographs and prepare figures, of currently available commercial products and techniques for monitoring, management and control of Oomycete root and stem rot pathogens.


  1. Prepare a set of subject and sector relevant factsheets* using information collected in objective 1 above together with key scientific findings of importance and the generic overviews of ‘detection and diagnosis’, ‘management and control’, and ‘integrated control’ from the HDC Desk Study (CP126).


{*fact sheets would be prepared to ‘stand alone’, but might follow a general narrative and be written and designed to be collected together as ‘chapters’ in a grower guide if this is considered desirable by HDC}.


  1. Organise, help run through HDC, and chair, a series of 4 Grower Workshops to be presented at locations and on dates agreed with HDC.  These will include presentations of the findings of this project and hands-on demonstrations of topics like diagnostic techniques and microscopy (with camera plus large screen), as well as promotions of fact sheets and where possible and in agreement with HDC, invited stands, posters and speakers on relevant topics or products.


  1. Preparation (subject to HDC approval) of 4-6 ‘YouTube clips’ showing topics relating to the Grower Workshops that might also benefit from an in situ presentation.  For example: On-site Grower/consultant ‘fly on the wall’ targeted tour looking at where key areas of concern could be addressed by visual and technical discussion e.g. i) rain water harvesting - collecting apparently clean water from greenhouse roof – membrane filter it – see discoloured membrane and look at some plates prepared earlier; ii) using on-site diagnostics kits on a  range of materials (e.g. possibly swabs from various surfaces?); iii) demonstrating how bio-filters work or iv) testing soils for Pythium.  These ‘clips’ could serve as aide memoirs for the workshops and might also help to promote them.


Benefits to the industry:


  1. For Levy payers :

The primary benefit from this KT project will be the promotion of current best practice on detection, diagnosis, monitoring, management and control of root and stem infecting Oomycete pathogens of importance (or potential importance) to UK horticulture.This will inform improvements in current practice and increase the efficiency and value-for-money of future research and development programmes on the diagnosis, biology and control of these important disease problems by:

  • Providing a series of Factsheets that accessibly present technical and relevant scientific knowledge that will inform, update, (and remind) current grower practice on currently applicable/available diagnostics, water treatments and control measures & disease prevention.
  • Presenting a series of Grower workshops to promote the Factsheets and stimulate discussion and participation in hands-on activities, and encourage uptake and maintenance of current and forward-looking good practice.
  • Producing some ‘YouTube clips’ to generate interest in the KT project and thereby promote current best practice.
  • Reducing the current considerable risk of unnecessary duplication/repetition of research effort both in time and between sectors that comes from the poorly-informed piece-meal approach to applications for funding resulting from the lack of clear and accessible knowledge of what has gone before.
  • Identifying areas where future research will yield economically useful results in short, medium and long-term.
  1. For Consumers:

The aim of this project is to inform and improve best horticultural practice in monitoring and controlling Oomycete root and stem pathogens.  This should help improve control of these pathogens, and thus help deliver high quality produce and hopefully help reduce reliance on fungicide application, thus reducing residue risk


  1. For the Environment:

There are likely to be some longer-term positive environmental benefits, especially if this project encourages further use of sustainable practices such as:

  • safe collection and re-use of waste water, thus significantly reducing risks of environmental contamination through disinfectant and/or pesticide use.
  • reductions in crop protection inputs and therefore also energy use and greenhouse gas emissions
  • improved ability to react fast to emergence of new disease threats

adoption of disease control systems that can form part of lower-input sustainable farming systems