Emphasising the effectiveness of control - and not risk from infection - may be key to combating pathogens

  • 06
  • FEB
  • 2020

When it comes to crop diseases, educating growers about the effectiveness of control strategies is more important than emphasising the risks posed by the disease, according to new research led by Rothamsted. 

Disease-control campaigns help to combat plant pathogens that threaten crops, but are only successful if they are sufficiently well coordinated and if enough growers and other stakeholders comply. 

However, most mathematical models of disease control have neglected how people’s opinions of disease-control strategies influence their decisions to participate.

To better understand how opinions affect the success of a control campaign, Dr Alice Milne and colleagues coupled a mathematical model of the spread of citrus huanglongbing disease (HLB) with a model of human behavior that incorporates findings from a survey of growers.

HLB threatens citrus production around the world, and can only be controlled if neighboring growers coordinate use of pesticides and other control strategies.

A CLas-infected orange tree in the foreground with healthy trees in the background.  The yellow shoots or “Dragons” are a prominent symptom giving huanglongbing (HLB) [Chinese for ‘yellow dragon disease’] its name.

Analysis of the combined models’ predictions highlights the importance of maintaining frequent engagement between growers and people who provide advice and support on HLB control. 

It also suggests that educating growers about the effectiveness of control strategies may be far more important than emphasizing how much of a risk HLB poses to crops. 

Dr Milne said: "Many campaigns focus on disease risk, but doing so may be unnecessary and lead to loss of trust if an epidemic never actually occurs.

“This study shows the importance of cross-disciplinary approaches to tackle serious disease outbreaks. We used an infectious disease of citrus trees, but our results are likely applicable to serious human diseases, as well.”

Next, the researchers plan to investigate other systems in which human behavior plays an important role in programs to monitor and control invasive pests or diseases. 

This will involve deeper exploration of stakeholder values and motivation, as well as development of new methods to represent these viewpoints in mathematical models.

These current findings appear in PLOS Computational Biology and also involved researchers from the USDA, the University of Salford, and Curtin University.

About Rothamsted Research
Rothamsted Research is the longest-running agricultural research institute in the world. We work from gene to field with a proud history of ground-breaking discoveries, from crop treatment to crop protection, from statistical interpretation to soils management. Our founders, in 1843, were the pioneers of modern agriculture, and we are known for our imaginative science and our collaborative influence on fresh thinking and farming practices.
Through independent science and innovation, we make significant contributions to improving agri-food systems in the UK and internationally. In terms of the institute’s economic contribution, the cumulative impact of our work in the UK was calculated to exceed £3000 million a year in 20151. Our strength lies in our systems approach, which combines science and strategic research, interdisciplinary teams and partnerships.
Rothamsted is also home to three unique resources. These National Capabilities are open to researchers from all over the world: The Long-Term Experiments, Rothamsted Insect Survey and the North Wyke Farm Platform.
We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT).
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1Rothamsted Research and the Value of Excellence: A synthesis of the available evidence, by Séan Rickard (Oct 2015)

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About LAT
The Lawes Agricultural Trust, established in 1889 by Sir John Bennet Lawes, supports Rothamsted Research’s national and international agricultural science through the provision of land, facilities and funding. LAT, a charitable trust, owns the estates at Harpenden and Broom's Barn, including many of the buildings used by Rothamsted Research. LAT provides an annual research grant to the Director, accommodation for nearly 200 people, and support for fellowships for young scientists from developing countries. LAT also makes capital grants to help modernise facilities at Rothamsted, or invests in new buildings.