Pests and diseases already destroy about a third of potential cocoa production, and with climate change there will be a greater threat to future supplies of cocoa.

Raw sugar prices climbed to their highest level in 29 years on 1 February, with raw sugar ­for March delivery reaching 30.05 US cents a pound in early afternoon trading on ICE Futures US.

Mali had some 30mn chickens, ducks, guinea fowl and turkeys in 2005, but not enough protein-rich poultry products are consumed locally, according to the government and nutritionists.

Organic farming is a promising pursuit for small farmers in many of the world´s poorer nations.

Even the highly drought-resistant cowpea (a long type of legume) now has an increasingly difficult time surviving in the Sahel countries.