I have posted this link here before, I will post it again because knowledge is power.
http://66.102.7.104/search?q=cache:M-PAYG8gE9QJ:www.sarpn.org.za/documents/d0001190/P1320-property_rights_Zimbabwe_Richardson.pdf+Craig+Richardson+property+rights+zimbabwe&hl=en

Its simply untrue that commercial farmers did not supply a significant amount of food, its simply untrue that the primary cause of food insecurity in Zimbabwe is drought, its simply untrue that the so called smart sanctions are the reason Zimbabwe is about to implode.

Kristine, yes indeed agricultural subsidies make competition hard if not impossible for farmers in Africa, however the highly productive commercial farmers appear to have no problems competing, and you must also remember, Africa has to import 60% of its food over long distances, this gives a competitive advantage to local grown produce.

I have read this over and over in the Zimbabwe newspapers, its far cheaper to buy local than to import so while your point has some merit it simply does not apply in this situation.