The Teucrium Corn ETF (CORN) is down 14% thus far in 2015, but the coming seasonal harvest in the northern hemisphere could make corn prices pop again, said Sal Gilbertie, president of Teucrium Trading.'China and the United States, the world’s two largest corn producers, all that corn comes to market between basically the middle of September and the middle of December,' said Gilbertie. 'When that happens you often - not always but often - get a price decline and that’s a good time to come in.' Gilbertie added that corn competes for soybeans for acreage and the drop in corn has subsequently pulled down soybean prices. The Teucrium Soybean ETF (SOYB) is down 14% thus far in 2015. 'Soybeans are coming off very low inventories for multiple years and this was the first year we really had a good harvest,' said Gilbertie. 'Also we’ve had bumper crops in the southern hemisphere which is also very important for soybeans.' Meanwhile, the strong dollar has been especially unkind to wheat prices along with huge bumper crops globally. The Teucrium Wheat ETF (WEAT) is down 25% year-to-date. 'Wheat is finding some support right now as we speak,' said Gilbertie. 'It’s the most political of commodities besides oil people say, so wheat will be back.'