A number of fertilizer companies are sinking after fertilizer maker Mosaic (MOS) reported weaker than expected first quarter results. Mosaic indicated on slides that it presented on its earnings conference call that fertilizer prices haven't risen in tandem with grain prices. The weaker macro environment and greater supply uncertainty are two of the reasons for this discrepancy, the company said. Meanwhile, potash shipments are expected to decline in 2012 versus 2011, as China and India have delayed making potash purchases, Mosaic indicated. However, Mosaic expects potash shipments to rebound significantly in 2013, and surpass 2011 levels, while the outlook for potash prices is fairly stable. In mid-morning trading Mosaic dropped $2.30, or 3.97%, to $55.71. Meanwhile, Potash Corp. (POT) dropped 2.22% to $42.72, CF Industries (CF) fell 1.55% to $221.03 and Agrium (AGU) lost 0.56% to $104.94.