U.S. wheat fell on May 7, after climbing to its highest in 13 months, as a heat wave hit the plains states and political turmoil in Ukraine threatened to reduce supplies.

Soybeans fell for a third consecutive session and was trading near the one-month low from May 6, due to rising global oilseed supplies and slowing demand from China.

Chicago Board of Trade (CBOT) July wheat fell 0.3 percent to $7.36-1/2 a bushel. Front-month May wheat contract fell 0.2 percent to $7.29-3/4 a bushel, after closing up 1.5 percent in the previous session when prices hit $7.35, the highest spot price since early April 2013.

July soybeans fell 0.3 percent to $14.54-1/4 a bushel, not far from $14.43-1/4 a bushel from Tuesday, its lowest since April 7. July corn rose 0.2 percent to $5.18-3/4 a bushel.

The Chicago wheat market was pausing while it awaited U.S. Department of Agriculture (USDA) reports on May 9, Arnaud Saulais of Starsupply Commodity Brokers said in a Reuters report. "It is common to see the markets pull back one or two days before the USDA reports, although wheat is still well supported by the hot weather in U.S. grain belts."

Temperatures in parts of the southern Plains topped 100F on May 5, and unseasonably high temperatures and high winds persisted on May 6.

On May 9, the USDA on will release its first official production estimate of the U.S. wheat crop, along with initial forecasts for U.S. and world grain 2014-15 ending stocks.

"I do not think U.S. wheat is facing a resistance level; it is more of a general pause in the market," Saulais said.

The USDA said 31 percent of the U.S. winter wheat crop was in good to excellent condition, down from 33 percent a week earlier.

As for the U.S. corn crop, the USDA said it was 29 percent seeded, lagging the five-year average of 42 percent and behind an average trader estimate of 33 percent.

Wheat and corn were drawing support as fears grew that Ukraine’s exports could be curbed. In China, demand for soybeans were slowing.