Winter wheat condition was rated at 63 percent good to excellent, 29 percent fair and 8 percent poor or very poor and 95 percent emerged, compared with the average of 98 percent.
Flat to weaker in rangebound trade, hovering just above contract lows as the USA harvest progresses. Funds hold a large net short position in CBOT corn futures, leaving the market vulnerable to bouts of short-covering.
The USDA said private exporters sold 133,096 tonnes of US corn to unknown destinations for delivery in the 2017/18 marketing year, which began September 1.
The soybean harvest is nearing completion, while the corn harvest is still 17% points from being finished, behind its five-year average.
USA delegation visits Israel to soothe concerns over Syria ceasefire deal
According to reports, the new ceasefire agreement would allow for Iranian troops to remain some 5 kilometers from Israel's border. On Tuesday, Lavrov said Iran maintained a "legitimate" presence in Syria, according to the Interfax news agency.
The most active corn contract for December delivery went down 1.25 cents, or 0.36 percent, to 3.4225 dollars per bushel.
Higher on bargain buying a day after the benchmark January contract dipped to a one-month low.
The National Agricultural Statistics Service reported Monday that 93 percent of the corn and 91 percent of the soybeans have been cut in the state. The Brazilian weather forecast is wet with heavy rains, which are expected to cross the northern and central areas of the crop belt through early December.
January soybeans went down 3.75 cents at 9.705 USA dollars per bushel as of 1610 GMT in the morning trading, December corn was down 2.5 cents at 3.3975 dollars, while December wheat was up 4.25 cents at 4.285 dollars.