Malting Barley Production In A Challenging Policy Environment

Published on 17 March 2009 in Sustainability and Communities

Introduction

The malting barley industry requires varieties which provide both a stable yield and a quality product for distilling and brewing. This is a challenge in a business environment full of uncertainty and risk. The purpose of this project is to improve disease management of barley through the development of more durable variety resistance which will lead to a reduction in fungicide use. It will also assist the industry achieve the stability and quality it requires to succeed. Maintaining effective varietal disease resistance over several cropping years has its challenges since the fungal pathogens which cause disease continually change and break down the varietal resistance. Unpredictable weather events which are one consequence of climate change also make disease forecasting a greater challenge. Changes in the types of pathogens or the populations of existing pathogens also increase uncertainty in providing malting barley requirements of the industry. Changes to pesticide legislation will also lead to an increase in uncertainty and the challenge will be to make fungicides the last line of defence as opposed to the way they are used today as the first line of defence to manage disease.

Key Points

The two key methods to manage plant disease are the use of resistant varieties and fungicides.  Over-reliance on either of these methods can lead to changes in pathogen populations resulting in the breakdown of host resistance and development of resistance of pathogens to fungicides.

This research will lead to improvements in the durability of disease management by several routes.

• Better targeting of fungicides through improved understanding of barley diseases
• Diversifying the range of mechanisms exploited in host defence including disease avoidance, induced resistance, disease tolerance and crop diversification
• Identification of novel resistance genes which can be used by breeders in future barley breeding programmes
• Improved disease forecasting and risk assessment

The approaches taken in the research need to be both economically viable and environmentally sustainable.

Research Undertaken

Barley seed is now recognised as a major source of inoculum for both rhynchosporium and ramularia. For ramularia, seed infection is a key source and airborne spores only appear once symptoms have developed. For rhynchosporium, seed infection is one of many sources of infection and weather conditions, for example, rainfall can exert a considerable influence on disease epidemics.

Crop disease (Ramularia) kills plants leading to loss of yield and quality required by the malting barley industry

Future methods of disease management will focus on seed health through non-chemical methods of control and greater knowledge on the pathogens present on seed and the movement of seed from one country to another.

Policy Implications

The malting barley industry’s requirement to use a single variety over a long period of time is currently only achievable through the reliance on fungicides to manage disease, particularly in the later years of a variety's lifespan. This research demonstrates alternative methods to fungicides, but the unpredictability of disease outbreaks through changes in the pathogen and environment as a consequence of extreme weather events mean fungicides will continue to be required as a method of last resort to manage disease.

Author

Dr Simon Oxley, Senior Researcher (Plant Pathology), SAC simon.oxley@sac.ac.uk

Topics

Sustainability and Communities

Comments or Questions