Most researchers whose life’s work is addressing the prevalence and impact of plant viruses say they aren’t a new agricultural problem, writes Cara Oltman at Syngenta’s THRIVE Magazine. But viruses evolve and adapt rapidly, posing a challenge that’s intensifying over time — intensifying as in causing $60 billion in crop losses worldwide, according to a 2019 estimate. Pre-pandemic, we might have referred to this growing threat as “going viral” — after all, we are talking about viruses. Since this feels like a good time to retire that phrase, let’s instead say we have a problem with microorganisms going macro.
It’s an impact that can devastate a field. For instance, the Soybean Research & Information Initiative reports:
- Yield losses of nearly 52% in southern germplasm due to bean pod mottle virus (BPMV).
- Losses from soybean mosaic virus (SMV) as high as 94%.
- Complete yield loss in many cases when both BPMV and SMV infect soybeans, because symptoms are more severe than those either virus produces alone.
The double whammy of BPMV and SMV is one instance of a phenomenon known as viral synergism.
Viral synergism and climate change are among the factors contributing to the prevalence and severity of viral disease, according to associate professor and South Dakota State University Extension plant pathologist Emmanuel Byamukama, Ph.D.
“Viral synergism, when multiple species are playing tag team in an infected plant, has been observed more frequently and can result in increased accumulation of one or more viruses, causing more severe symptoms than if only one was present,” Byamukama says.
In regard to climate change, he says, warmer temperatures for longer periods of time extend the reproduction period and life span of insect vectors, allowing more opportunity for virus transmission.
