Skip to main content
Research article - Peer-reviewed, 2021

Using risk models for control of leaf blotch diseases in barley minimises fungicide use - experiences from the Nordic and Baltic countries

Jorgensen, Lise Nistrup; Matzen, Niels; Ficke, Andrea; Andersson, Bjorn; Jalli, Marja; Ronis, Antanas; Nielsen, Ghita C.; Erlund, Patrik; Djurle, Annika


The disease pressure from Pyrenophora teres, Rhynchosporium graminicola, and Ramularia collo-cygni varies widely between years and locations, which highlights the need for using risk models to avoid unnecessary use of fungicides. Three disease risk models were tested in thirty-three ?eld trials during two seasons in ?ve countries in order to validate and identify situations favourable for barley leaf blotch diseases in the Nordic-Baltic region. The tested models were: The Crop Protection Online (CPO), which uses number of days with precipitation (>1 mm), cultivar resistance and disease data as basis for risk assessments; the humidity model (HM) which signals a risk warning after 20 continuous hours with high humidity, and the Finnish net blotch model (WisuEnnuste), which calculates a risk based on previous crop, tillage method, cultivar resistance and weather parameters. The risk models mostly gave acceptable control of diseases and yield responses compared with untreated and reference treatments. In the dry season of 2018, the models recommended 88-96% fewer applications than the reference treatments, while in 2019, the number of applications was reduced by 0-76% compared to reference treatments. Based on yield increases, the recommendations were correct in 50-69% of the trials compared to one-treatment references and 69-80% of the trials when references used mainly two treatments.


Humidity model; Crop Protection Online; net blotch; scald; ramularia leaf spot; WisuEnnuste

Published in

Acta Agriculturae Scandinavica, Section B - Soil and Plant Science
2021, volume: 71, number: 4, pages: 247-260

Authors' information

Jorgensen, Lise Nistrup
Aarhus University
Matzen, Niels
Aarhus University
Ficke, Andrea
Norwegian Institute of Bioeconomy Research (NIBIO)
Jalli, Marja
Natural Resources Institute Finland (LUKE)
Ronis, Antanas
Lithuanian Research Centre for Agriculture and Forestry
Nielsen, Ghita C.
Erlund, Patrik
Nylands Svenska Lantbrukssallskap
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology

Associated SLU-program

SLU Network Plant Protection

UKÄ Subject classification

Agricultural Science

Publication Identifiers


URI (permanent link to this page)