Cargill, the US agribusiness conglomerate, on Tuesday warned that the global economy was “still fragile” as it said profits in the three months to the end of August had plunged by 65 per cent from last year, dragged down by poor fertiliser sales.

The results underline how the US agricultural sector continues to struggle as the drop in commodity prices and tighter credit markets force farmers around the world to cut demand for inputs such as fertilisers. Cargill is the world’s largest trader of agricultural commodities.