There won't be any sources for a while because this is literally just starting.
I mean 3billion people are on lockdown of some sort globally right now. Not hard to imagine it may be hard for workers to get to farms across borders, or even within borders. CA alone will probably see a shortage of migrants. No, I don't know for sure but I'm speculating that it's quite likely.
Supply chains have also been strained because people have been panic buying for what, 3 weeks now? You can't just snap your fingers and double your supply of vegetables.
Even if you do nothing the market will probably fix it: Less food in the markets > high demand drives up prices > higher salaries > slightly lower prices
At some point some people are hungry enough to get a... shall we say... real job?
With some regulatory sanity we subsidize it a bit.
Perhaps we should test and quarantine the farm workers when money stops being an issue.
Especially with anti-price-gouging laws - this process is explicit forbidden from happening during a crisis.
Also, its also not that simple as stated by op.
Its also a supply chain issue. Which could be worse than anything else.
Drivers getting sick. Cargo ship captains getting sick etc etc etc.
Stuff might stop coming even if available in China.
How do you repair your farmers tech? Especially sometimes it is licked behind a paywall, where you cant just use any wheel. It must be from company xxx.
We will find out soon that those paywalls will cause real real real world issues