Corn and soybean futures fell in the United States on Thursday following good weather forecasts for crops over the next few days.
Other factors included a firm dollar, a downturn in crude oil prices and weak equity markets.
Corn prices have fallen nearly 10% this week since the Agriculture Department announced that despite a cold and wet spring, farmers this year planted the second-largest amount of corn since 1946.
A total 35.2 million hectares were planted with corn.
US grain markets will be closed on Friday for the 4 July Independence Day holiday.
However, soybean futures are up 4.3% due to fears of shortages at processors and export terminals during summer.
Wheat prices also eased on Thursday due to a glut of global supplies.