December corn opened 2 cents lower on the day at 585 3/4 and established an early range of 585 to 596 3/4. Corn opened lower in line with a weaker overnight market. Traders said that the International Grains Council's latest estimate of world corn production was also a factor. The IGC raised world production by 15 million tonnes to 774 million tonnes. In spite of the negative news, prices rallied to higher on the day in what traders said was a short covering rally ahead of the long holiday weekend. Today's deliveries against the September contracts were revised after open. The corn delivery figure was lowered to 203 contracts from a previously announced figure of 636 contracts. This is more in line with conditions in the cash markets which are tight both in the interior and at the Gulf.