Nigeria, May 1 -- On a Saturday morning in early January, farmers in Abana, a farm settlement in Ondo West Local Government Area, lined a narrow path as they headed into the forest for the day's labour. The settler farmers had grown cocoa, kolanuts and oil palm in the area for generations. The mood was upbeat among the farmers as the cocoa season had just opened with the price shooting up to unprecedented levels due to the plummeting value of the naira, the Nigerian currency.

At about N10,000 per kilogramme, a tonne of cocoa would make a farmer a multi-millionaire.

But their moods quickly changed to apprehension as they approached their farms and the sound of heavy equipment became louder. They knew what the sound foreboded. Workmen, wi...