Grain markets faced pressure as technical selling pushed prices lower across the board. December Corn futures fell near session lows, closing below the 450'0 level despite flash sale announcements of 315,000 metric tons to Mexico. January Soybean futures tested the 200-day moving average near 1200'0 as the U.S. harvest advanced to 88% complete. Meanwhile, Chicago Wheat futures traded lower near 590'0 to 600'0, with crop conditions trailing estimates as winter wheat planting hit 83% complete.