What agricultural challenges do africans face, and how do these affect food production in the continent?

Lack of information on  new farming methods E.G. crop rotation and the use of green manure
Lack of financial support, Poor transportation systems
They have to farm on the same land, because they can only afford small amounts.. which leads to them over-suing it and it loses its natural nutrients and becomes barren
Due to being far away and not having transport, by the time the want to sell some goods, they have become rotten, this is also because they dont have fridges and freezers to store them in

Thats about all I can think of :)