I would hate to be the farmer who negotiates a lucrative deal with a Heinz/Kraft factory to sell my crop at a substantial profit only to be told by the company, sorry, the government has decided that we’ve purchased too many tomoatoes already, you’ll have to find some small company to buy your crop so we can be fair. The market alone should control the market.
Heinz, Campbell's, Hunt's and other major tomato processors contract with farmers at fixed prices for processing tomatoes before planting often providing proprietary tomato seed and crop advances. Farmers don't want to bring a highly perishable tomato crop to market without a fixed price.