CANBERRA: US wheat futures rose 1.5% to touch a one-week high on Tuesday after the US Department of Agriculture pegged the condition of crops below market forecasts, stoking concerns about global supplies.

Corn firms, drawing support from wheat, while soybeans were little changed.

The most active wheat futures on the Chicago Board Of Trade were up 1.5% at $6.75 a bushel by 0504 GMT near the session high of $6.76-1/4 a bushel - the highest since June 14. Wheat closed up 0.3% on Monday.

Analysts said wheat was drawing support from the USDA crop condition report.

"The survey recorded another drop in the condition of the US spring wheat crop," said Tobin Gorey, director of agricultural strategy, Commonwealth Bank of Australia.

"The production outlook for high-protein wheat continues to dim."

The USDA said crop ratings declined sharply last week, although rains last weekend were likely to aid supplies. The USDA said just 27% of the crop was in good-to-excellent shape, a 10-point drop that was well below expectations.

The most active soybean futures were little changed at $14.15 a bushel, having firmed 0.5% on Monday.

Soybeans were rated 60% good to excellent, in line with analyst expectations, but down 2 points from a week earlier. The USDA also said the US soybean crop was 97% planted, on par with trade expectations.

Soybean futures have drawn support from USDA confirmation on Monday of renewed buying by China, first reported by Reuters on Friday, the country's largest scale purchases in four-and-a-half months.

The most active corn futures were up 0.6% at $6.63-1/4 a bushel, having closed down 0.6% in the previous session.

The US corn crop was rated to be 65% in good-to-excellent shape as of Sunday, down 3 percentage points from a week earlier and a point lower than the average estimate in a Reuters survey of 11 analysts ahead of the report.