Challenges in Ramularia collo-cygni Control

Riinu Kiiker,Andres Mäe

doi:10.3390/encyclopedia2010017

Abstract

Ramularia leaf spot (RLS), caused by the fungus Ramularia collo-cygni, has recently become widespread in Europe. Succinate dehydrogenase inhibitor (SDHI) and demethylation inhibitor (DMI) fungicides are mainly applied for disease control on barley fields, but pathogen isolates with a reduced sensitivity can cause difficulties. There is an urgent need for new spring barley cultivars that are more resistant to RLS development and can inhibit R. collo-cygni epidemics.

Highlights

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The trigger of these increasing Ramularia leaf spot (RLS) epidemics is still under debate, R. collo-cygni adaptation to widely distributed RLS-susceptible barley cultivars and fungicides along with heat stress under global climate change will lead to a risk of future RLS epidemics [3,6]
Genetic studies have shown highly admixed R. collo-cygni populations without geographical clustering, which emphasizes the significance of the global seed market and delivery in spreading the pathogen genotypes and accelerating the spread of fungicide resistance [22]

Summary

Introduction

RLS was a minor disease and did not cause any serious problems in barley cultivation, but the majority of R. collo-cygni outbreaks have been reported in the last few decades. Since the beginning of 2000, RLS has been considered to be an emerging disease of barley in Europe, South America, and New Zealand [2,4,5]. It is possible that RLS can lead to moderate barley yield losses of 5–20% or greater. The trigger of these increasing RLS epidemics is still under debate, R. collo-cygni adaptation to widely distributed RLS-susceptible barley cultivars and fungicides along with heat stress under global climate change will lead to a risk of future RLS epidemics [3,6]

Epidemiology of Ramularia collo-cygni

Status of DMI-Fungicide Sensitivity

Status ofobserved

Findings

Pleiotropic