Grain markets coped with losses and new uncertainty this week as the latest U.S. crop production numbers from the U.S. Department of Agriculture (USDA) pointed to higher-than-expected yields and China’s central bank devalued its currency approximately 4.4 percent over three days.

China announced Tuesday it would devalue its currency, the renminbi, and continued the process Wednesday and Thursday.

The move caught traders globally off guard, which prompted heightened market reactions and significant, mostly negative, speculation about what led to the move and what its long-term effects would be.

In the short term, other Asian currencies fell, and U.S. exports suddenly became more expensive for Chinese buyers.

Mid-day Wednesday, commodity markets received another shock when the latest USDA World Agricultural Supply and Demand Estimates (WASDE) report – watched closely due to corn pollination timing – reported an expected increase in U.S. corn yields and total production for the current crop year. Commodity prices plummeted on the news, with corn and soybeans taking the hardest hit.

The USDA estimated corn production for 2015/2016 crop year at 347.6 million metric tons (13.7 billion bushels), 4 million tons (157.5 million bushels) higher than last month’s estimates, with estimates for average yields increased from 166.8 bushels per acre (10.5 tons per hectare) to 168.8 bushels per acre (10.6 tons per hectare). While the percentage increase is relatively small, it was surprising and on the heels of the China moves.

On the competition front, the USDA also increased Brazil’s corn export estimates by 1.5 million tons (59 million bushels), Argentina’s by 0.5 million tons (19.7 million bushels) and the Ukraine’s by 1.5 million tons (59 million bushels) while the U.S. corn export estimate was reduced by 1 million tons (39.4 million bushels), from 48 million tons (1.9 billion bushels) in July to 47 million tons (1.85 billion bushels) in Wednesday’s report.

The European Union is facing a heat wave that will lower its corn crop, according to USDA, and increase corn imports by an estimated 1 million tons (39.4 million bushels).

Both the pricing and export estimates point to a need for strong market development efforts for U.S. grains to continue to show customers the value and stability of the coming crop and the U.S. agricultural system.