Global food crisis: what went wrong

In a recent speech in India, Lamy made some interesting statements, including the following:

"The negotiations in the WTO on agriculture subsidies and market access are part of the medium and long term solution to the food shortage. We know that we need to increase agriculture production in developing countries and one of the reasons why their production and exports have been discouraged is because of trade distorting subsidies and high tariffs in rich countries."

One can't help wondering what are the other possible reasons?