Prices that had slumped to the lowest on record in February surged almost 19% in the four days leading up to the trading spike on Friday
Top African producer Burkina Faso bans genetically modified cotton, says US giant Monsanto variety 'poor quality'
High-profile critics claim victory after country says GM cotton, though producing higher yields, has caused a drop in crop quality.
Five developing countries - Brazil, Argentina, India, China and South Africa - grew almost half of all GM crops in 2015
The cash crop had been one of those that escaped the rout in commodity prices, but the pain could be coming home.