Plant diseases must be monitored to protect the food supply

In a new commentary from McGill University, experts say that plant disease surveillance and improved detection systems are needed to mitigate future disease outbreaks and protect the global food supply.

Plant diseases do not stop at national borders and even miles of oceans cannot prevent their spread, explained the researchers.

According to lead author Professor Jean Ristaino of NC State University, the idea is to detect these plant disease outbreak sources early and stop the spread before it becomes a pandemic. He noted that once an epidemic occurs it is difficult to control, just like COVID-19.

“We’ve seen how important information sharing, data analytics, and modeling have been in responding to the COVID-19 pandemic,” said co-author Professor Graham MacDonald. “These types of tools could also be leveraged to help build resilience to future plant disease outbreaks – from identifying risk in global crop trade networks to local citizen science monitoring.”

Some plant diseases are already under surveillance, such as wheat rust and potato blight, but others are not regularly monitored. 

“There are a few existing surveillance networks, but they need to be connected and funded by intergovernmental agencies and expanded to global surveillance systems,” said Professor Ristaino. “We can improve disease monitoring using electronic sensors that can help rapidly detect and then track emerging plant pathogens.”

The experts noted that global plant disease outbreaks are increasing in frequency and threaten the global food supply. In 2019, plant diseases and pests caused average losses of up to 30 percent to major food crops such as wheat, rice, and maize. 

Climate change will likely exacerbate outbreaks of plant diseases. In Africa, for example, temperature changes and drought conditions influence fluctuations in locust populations, which devastate crops.

“More frequent rainfall can allow airborne plant pathogens to spread and fungal spores can move with hurricanes, which is how soybean rust came to North America from South America – via storms,” said Professor Ristaino.

“There are also cases of early emergence, when pathogens emerge earlier in the growing season than usual due to warmer springs.”

The global food trade is also driving outbreaks of plant diseases. The emergence of new pathogens puts a strain on the food supply.

“Globalization means that agriculture and food supplies are increasingly interconnected across national borders. Analyzing these crop trade networks combined with greater information sharing among countries can help to pinpoint risks from pests or diseases,” said Professor MacDonald.

The research is published in the journal Proceedings of the National Academy of Sciences.

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By Chrissy Sexton, Earth.com Staff Writer