Management boards have not worked historically. One example might be the Australian Wheat Board. A second example is the Canadian Wheat Board.
On the supply side production management has not proved successful that I'm aware of.
The demand side is a little different. Egypt is the world's largest importer of wheat and GASC (basically the same as the production boards but for buying) has generally been one of the best traders. They're good for the most part. They're generally clever.
Free markets work best in my personal opinion. But for production side I don't see broad-scale management working, while on the consumption side it actually can work.