The steady growth of the U.S. economy has caused the U.S. dollar to appreciate against the currencies of other nations such as Russia, Ukraine, Brazil, Argentina, Canada and Australia and can put American grain and oilseed exports at a disadvantage relative to competing origins.Shifting currency values are very much in the news these days. The steady growth of the U.S. economy, while the economies of other developed and developing countries have slowed, has caused the U.S. dollar to appreciate against most other currencies in nearly a straight line upward since July. In particular, it has strengthened against the currencies of nations such as Russia, Ukraine, Brazil, Argentina, Canada and Australia that export grains and oilseeds in competi...