* KC wheat leads as heat in Plains scorches developing crop
* Ukraine turmoil, weak U.S. dollar lend support
* Corn follows wheat up; slow U.S. planting pace lends support
* Soybeans down on ample Latin American oilseed supplies (New throughout; updates prices, adds quotes; changes byline, dateline, previous PARIS/SINGAPORE)
By Julie Ingwersen
CHICAGO, May 6 (Reuters) – U.S. wheat futures rose to their highest in 13 months on Tuesday, led by the Kansas City market as the southern U.S. Plains wheat belt remained in the grip of sizzling heat and dryness.
Corn followed wheat higher but soybeans fell for a second straight session as large South American soy harvests eased concerns about tightening supplies of old-crop U.S. soybeans.
At the Chicago Board of Trade as of 12:35 p.m. CDT (1735 GMT), most-active July wheat was up 12-1/2 cents at $7.41-1/2 a bushel. The May contract reached $7.35, the highest spot price since early April 2013.
The biggest gains were in KC hard red winter wheat, the type grown in the southern Plains. KC July wheat was up 20 cents at $8.52 a bushel after hitting $8.55-1/2, its highest in more than 16 months.
Temperatures in parts of the southern Plains topped 100 degrees Fahrenheit (38 Celsius) on Monday, and unseasonably high temperatures and high winds persisted on Tuesday.
Much of the region’s wheat, already stressed by months of drought, is in a key phase in which the kernel-bearing heads of the plants emerge from the stalks. The U.S. Department of Agriculture said 81 percent of Oklahoma’s wheat was heading as of Sunday along with 15 percent of the crop in Kansas, the biggest U.S. wheat state.
“Highs were 100 to 105 degrees Fahrenheit yesterday from central/southwest Oklahoma into west Texas, and similar readings today also reach into south-central Kansas before some moderation. Heading wheat will see significant loss,” the Commodity Weather Group, a meteorological firm, said in a daily note to clients.
The U.S. Department of Agriculture late Monday said 31 percent of the U.S. winter wheat crop was in good to excellent condition, down from 33 percent a week earlier.
“There has been a lot of increased coverage about dry conditions out west, bringing into the public view that we have some drought issues in farmland,” said Shawn McCambridge, a grains analyst with Jefferies Bache in Chicago.
Additional support stemmed from political turmoil in Ukraine and its port city of Odessa, where more than 40 people were killed on Friday in the worst day of violence since a February revolt toppled Ukraine’s pro-Russian president.
Ukraine is the No. 3 global corn exporter and a key supplier of wheat as well.
Also, the U.S. dollar fell 0.45 percent to a 6-1/2-month low against a basket of currencies, making U.S. grains more competitive on the global market.
Traders were waiting for the USDA on Friday to release its first official production estimate of the U.S. wheat crop, along with its forecasts for 2014/15 exports and ending stocks.
CBOT corn rallied from overnight weakness as wheat climbed, gaining against soybeans on inter-market spreads. CBOT July corn was up 9-1/2 cents at $5.17-1/2 a bushel.
Traders continued to mull the prospect of U.S. planting delays after the USDA late Monday said the U.S. corn crop was 29 percent seeded, lagging the five-year average of 42 percent and behind an average of trade estimates for 33 percent.
Farmers are able to seed large areas quickly if they get a window of clear weather. But many in the Midwest prefer to plant before mid-May.
“Even if you get down to the last 5 percent, we are still talking about a lot of acreage that is at risk of not getting planted,” McCambridge said. “Especially if Ukraine can’t do much on the export side, there is not a lot of room to absorb losing a couple of million acres,” he said.
Some acres intended for corn may get switched to soybeans, a bearish factor for new-crop soybean futures.
Soybean futures fell for a second session on profit-taking and plentiful supplies in South America. CBOT July soybeans were down 3-1/4 cents at $14.60 a bushel.
“Soybeans are being pressured by simple technical profit taking and technical weakness. Demand has slowed considerably for U.S. soybeans,” said Karl Setzer, a CTA with the MaxYield Cooperative in West Bend, Iowa.
Prices at 12:28 p.m. CDT (1728 GMT) LAST NET PCT YTD CHG CHG CHG CBOT corn 517.25 9.25 1.8% 22.6% CBOT soy 1457.00 -6.25 -0.4% 11.0% CBOT meal 475.90 -2.70 -0.6% 8.7% CBOT soyoil 41.23 0.06 0.2% 6.2% CBOT wheat 742.25 13.25 1.8% 22.6% CBOT rice 1558.00 6.50 0.4% 0.5% EU wheat 215.50 -1.25 -0.6% 3.1% US crude 100.22 0.75 0.7% 1.8% Dow Jones 16,437 -93 -0.6% -0.8% Gold 1307.46 -2.04 -0.2% 8.5% Euro/dollar 1.3931 0.0057 0.4% 2.0% Dollar Index 79.1000 -0.3860 -0.5% -1.2% Baltic Freight 1022 5 0.5% -55.1% (Additional reporting by Sybille de La Hamaide in Paris and Naveen Thukral in Singapore; Editing by Jane Baird and James Dalgleish)