A conspiracy of microbes targeting lettuce.

A conspiracy of microbes targeting lettuce.

Good morning. 

Asaf Shalev here, writing to share my new cover story about a conspiracy of microbes targeting lettuce. At least it feels like one. Beginning at the end of last year—before the Covid-19 pandemic—the lettuce farmers of the Salinas Valley have been hit by one existential threat after another. 

First came a fast-spreading disease that caused lettuce leaves to turn brown, dry and dead. Then came another disease that rotted the roots of the lettuce and made the leaves wilt in the field. And after that, another sickness emerged—affecting faraway salad eaters who may have been contaminated by local lettuce. Canada, a major trading partner, all but banned lettuce from entering the country. 

It’s gotten so bad that some farmers are talking about abandoning lettuce as a crop, but that’s not only a problem for farmers. In the Salinas Valley, lettuce was a $1.36 billion crop in 2019, the biggest crop in the largest industry in Monterey County. An economic downturn in agriculture will have ripple effects for many others. 

There’s a business story here, then, but also a science story because to understand the challenges facing lettuce, you have to learn a bit about certain microbes, a virus, a water mold and a bacteria. Finally, the story is like a murder mystery: Who killed the lettuce? Meet the scientists who are on the case. 

Lettuce has become an intrinsic part of the Salinas Valley and the primary reason we are called the Salad Bowl of the World. It will be riveting to follow if, and how, we manage to come out of this crisis. 

-Asaf Shalev, staff writer, asaf@mcweekly.com