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 mountains.
And the smell of rot fills the country.

– John Steinbeck

The Grapes of Wrath, Chapter 25. In California there is a bountiful harvest and over-abundance of food. It goes to waste, because in order to keep up the price the farm owners believe it must be destroyed. We get the horrifying image of "golden mountains" of oranges having kerosene sprayed on them, while a million people go hungry. This is uncontrolled industrial farming and quest for profits run amok, as a corrupt economic system scales new heights of inhumanity. The "smell of rot" not only refers to the wasted food, but also to the rotten system. Steinbeck brands the farmers’ actions a "crime" and speaks of the farm employees’ anger at having to carry it out.