July corn opened 7 1/4 cents lower on the day session at 600 and established an early range of 595 1/2 to 602 3/4. The early weakness in corn took the July contract down to yesterday's lows. Traders indicate that selling comes from continued forecasts for good planting weather in the US, especially in the western corn belt. It is thought that corn planting may catch up to near normal levels by the middle of next week if current forecasts hold. China said today that it sees higher corn output in 2008. Basis levels in the interior are mostly steady to firm this morning on light farmer selling. Today is the last trading day in the May corn futures contract which expires at noon.