I was talking with someone in the produce business on a fairly large scale the other day. The issue was why so many seemingly illogical price changes. He said that today it is not who has the largest farm or an area with the most farms; it is who has the most refrigerated square footage. The people with all of this square footage can and do control prices for periods of time.
I have also read that on an international scale large corporations massively control prices from country to country. They might sell a lemon, hypothetically, for 50 cents in Mexico, 75 cents in France and $2.00 in the US. They price according to how much they think the populace can afford. These big corporation are willing to withhold product from the market to keep this system going even if they have to discard large inventories to do it.