“The works of the roots of the vines, of the trees, must be destroyed to keep up the price, and this is the saddest, bitterest thing of all. Carloads of oranges dumped on the ground. The people came for miles to take the fruit, but this could not be. How would they buy oranges at twenty cents a dozen if they could drive out and pick them up? And men with hoses squirt kerosene on the oranges, and they are angry at the crime, angry at the people who have come to take the fruit. A million people hungry, needing the fruit—and kerosene sprayed over the golden mountain.

"And the smell of rot fills the country.“ (Chapter 35)

This passage had a profound impact on me when I first read it in high school. Only later did I discover that such atrocities still happen regularly today.

Farms are mostly just businesses nowadays. Either they're heavily automated (and capital intensive) or they hire farm workers to do the work. Or both.