Switching off the (b)lights
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Pesticide resistance is an increasing challenge in crop production. The Teagasc-led project IPMorama seeks to drive crop resistance to mitigate issues around heavy pesticide use.
The European Commission’s Farm to Fork strategy aims to create a fair, healthy and environmentally-friendly food system. It sets ambitious goals to reduce, by 2030, the overall use and risk of chemical pesticides by 50% and the use of more hazardous pesticides by 50%.
A key element in achieving this is widespread adoption of integrated pest management (IPM) approaches – combining cultural, physical, biological and chemical tools in a way that maximises disease control whilst minimising risks to human health and the environment.
Current disease and pest management approaches in tillage crops incorporate many of the characteristics of IPM. However, one important element frequently underexploited – or missing completely – is using varieties that have been bred for resistance to pathogens and pests. To address this, Teagasc is co-ordinating a new Horizon Europe project called IPMorama, which started in September 2024.
Blight trials at Oak Park illustrate the devastating potential of late blight on potatoes. Photo credit: Teagasc
Dan Milbourne, the Teagasc Senior Research Officer coordinating the project, explains: “With 17 partners across 10 European countries, the goals of IPMorama are to develop an increased capacity to breed disease- and pest-resistant crops, while also developing IPM strategies that exploit these resistance characteristics to reduce the need for chemical pesticides. We call this variety-centric IPM.”
IPMorama will focus on wheat, potatoes and grain legumes (soy, pea and lupins), looking at important diseases and pests of these species, such as late blight and rust disease. The project will develop a whole practice ecosystem for variety-centric IPM, based on four main components.
Developing the tools
The first component involves developing tools to help breeders more effectively select for resistant plants, and will use these to develop resistant breeding lines that can be exploited by breeders during and after the project.
“As part of this, we’ll characterise the genes upon which the resistance is based, which is important because pests and pathogens can evolve to overcome these genes,” explains Dan. The second component is understanding the distribution of virulent pathogen strains capable of overcoming plant resistances: monitoring the emergence and prevalence of new strains and whether they can overcome available resistant varieties.
“This allows us to develop optimal IPM approaches for crops in the third component of IPMorama, in which variety-centric IPM solutions will be upscaled from experimental plot level to whole farm level,” Dan continues.
The fourth component is to upskill the entire crop value chain in the use of IPM tools and strategies developed in the project, and to understand the practical and societal barriers that might prevent their uptake.
The urgent need for IPM strategies that incorporate resistant varieties is illustrated by disease control problems currently being experienced in one of the IPMorama target crops, explains Principal Research Officer Steven Kildea.
“Unfortunately, the potato varieties we favour for food purposes are often extremely susceptible to late blight, caused by Phytophthora infestans. To prevent the disease from taking hold, farmers must regularly apply fungicides as the crops develop. Without doing this the Irish and wider European potato crop would fail.”
P. infestans presents a moving target through the rapid evolution of new strains. Since monitoring began, 46 such strains have been discovered. Whilst most have no real impact on blight control, some are resistant to important control fungicides.
Most recently, a P. infestans population called EU_43_A1 has been causing problems for blight control in Europe – developing resistance to not one but two of the key fungicides European potato growers rely upon to protect their crops.
Prior to the emergence of EU_43_A1, timely fungicide application of fungicides was a reliable method of keeping crops free of the disease, Steven explains.
“Unfortunately, the appearance of the first strains of EU_43_A1 in 2019 hinted at the limitations of this method. By 2022, it was clear that these strains had resistance to the important CAA fungicide family.”
“This by itself would be a significant issue. Then, following the summer of 2023 it became clear across parts of western Europe that – in addition to CAA resistance – strains of EU_43_A1 had evolved resistance to the completely unrelated OSPBI fungicide class.”
IPMorama practice ecosystem figure. Image credit: IPMorama
Facing the challenge
In September 2023, researchers detected CAA-resistant strains of EU_43_A1 in Oak Park, highlighting the potential threat of dual pesticide resistance in Ireland in the future. Because the threat to potato production of blight strains exhibiting resistance to multiple fungicides is so significant, the collective advice across Europe has unfortunately, been to apply more fungicide, Steven explains.
“Growers must mix different modes of action when treating crops, ensuring rates of fungicides are kept high, and must avoid delaying application – to counteract the possibility of late blight overcoming the crop, but also to prevent pesticide resistant strains from gaining a foothold”.
IPMorama can offer real solutions to this problem, suggests Dan.
“A new generation of potato varieties, with resistance based on both single and multiple blight resistance genes, is currently emerging on to the market. IPMorama will make the development of these varieties easier in the future. Multiple genes confer more durable resistance. However, we shouldn’t just release these varieties and rely on the resistance alone, as P. infestans may eventually overcome them.”
IPMorama will develop IPM strategies with accompanying decision support systems, whereby varietal resistance and fungicides will support each other, making it far more difficult for pathogens to overcome either. This will likely be achievable while also reducing the overall number of sprays required to control the disease.
Dan concludes: “It’s a win-win: securing the future of potato production in the face of this serious challenge, whilst at the same time becoming more sustainable.”
Funding
IPMorama – Integrating breeding for IPM into the deployment landscape for wheat, potatoes and grain legumes (Project 101135348) is a Research and Innovation Action, funded under Cluster 6: Food, Bioeconomy, Natural Resources, Agriculture and Environment of the Horizon Europe Work programme (2023-2024). Associate partners are supported by UKRI and SERI.
Contributors
Dan Milbourne, Senior Research Officer/IPMorama project coordinator, Crop Science Department, Teagasc Oak Park.
Steven Kildea, Principal Research Officer, Crop Science Department, Teagasc Oak Park.
You can find out more about the IPMorama project on the project's website