By Russ Blinch and K.T. Arasu

WASHINGTON/CHICAGO, July 18 (Reuters) - Oppressive heat and a worsening drought in the U.S. Midwest pushed grain prices near or past records on Wednesday as crops wilted, cities baked and concerns grew about food and fuel price inflation in the world's top food exporter.

Soybean prices at the Chicago Board of Trade set a record high and corn closed near a record as millions of acres of crops seared in triple-digit heat in the Corn Belt. Corn fields have been plowed up in many locations for lack of rain. Now soybeans, which develop later than corn, are in the bull's eye.

"I get on my knees every day and I'm saying an extra prayer right now," U.S. Agriculture Secretary Tom Vilsack told reporters after briefing President Barack Obama. "If I had a rain prayer or a rain dance I could do, I would do it."

Vilsack said the drought was getting worse for hard-hit farmers and the wilting crops will mean higher food prices.

"Part of the problem we're facing is that weather conditions were so good at the beginning of the season that farmers got in the field early, and as a result this drought comes at a very difficult and painful time in their ability to have their crops have good yield," Vilsack said.

Drought conditions now extend over more than 60 percent of the lower 48 states, the government said. The Department of Agriculture on Wednesday extended drought aid to an additional 39 counties designated as primary natural disaster areas, bringing such aid to a total of 1,297 counties across 29 states.

Vilsack said rising grain prices would mean meat and poultry prices will be higher this year and next, although the inflation may be delayed as farmers start culling their herds due to high feed prices and meat supplies stay adequate.

But the outlook for higher food prices could add up to another headache for Obama as he faces a November election with high joblessness and slower economic growth.

Hard-hit livestock producers and other groups want the Environmental Protection Agency to give oil refiners a waiver from the mandate to blend ethanol into gasoline, arguing demand for the corn-based fuel was driving up corn prices. About 40 percent of the U.S. corn crop now is used to produce ethanol.

But Vilsack said there was no need for such action as yet.

"There is no need to go to the EPA at this time based on the quantity of ethanol that is in storage," he said.

The U.S. drought is expected to be felt worldwide as the world's biggest grain exporter struggles with shortfalls. The United States exports more than half of all world corn shipments and is also the single top exporter of wheat and soy.

"The dramatic rise in grain prices in the past few weeks is shaping up to be a serious financial blow for wheat importing countries," one German trader said on Monday.

"African and Middle Eastern countries are now facing painful rises in import bills."

WEATHER OUTLOOK STILL HOT AND DRY

Forecasters were calling for scattered showers on Wednesday evening in some parts of the east coast and Midwest. But relief was seen as too little and too late for many of the key areas of the central Plains and Corn Belt.

"There are no soaking rains in sight, nothing to relieve the drought," said World Weather Inc meteorologist Andy Karst. "There will be some light rains today through Friday in the eastern Midwest."

Iowa and Illinois, which produce about a third of U.S. corn and soybeans, continued to swelter on Wednesday in temperatures at or above 100 degrees (37.8 degrees Celsius) with little to no rain forecast.

Corn prices have jumped more than 50 percent in the last month as the crop wilted in many locations during its key growth stage of pollination.

Corn for September delivery at the Chicago Board of Trade closed at $7.95 a bushel, near last summer's record high of $7.99-3/4. Soybeans for August delivery closed at $16.85-1/2, a new record high.

"Now, it's soybeans' turn. The next two weeks will be critical for them. There is a chance for catastrophic problems in soybeans," said grains analyst Don Roose of U.S. Commodities in Des Moines, Iowa

"The summer of 2012 is on pace to finish third hottest on the list of 62 summers since 1950," said Steven Root, a meteorologist with WeatherBank Inc. "But it is still in the running for number two or one."

In many parts of the country, power grids were under pressure from demand on air conditioning but most were holding up. In New York City, Consolidated Edison reduced its power voltage in some Manhattan neighborhoods, resulting in brownouts.

Low water levels in many lakes and rivers were hampering transportation, with hydroelectric plants tapping water in locations like Arkansas and the Army Corps of Engineers issuing warnings to consumers about water levels.

Water usage for lawns and recreation continued to see restrictions in many areas of the country.

In crop areas, farmers saw further headaches from plant diseases like fungus and crop pests like spider mites on soybeans or rootworms or Japanese beetles in corn that appear in hot weather.

But one silver lining in many areas from weeks of drought was a pleasant surprise: fewer mosquitoes, which lack moist breeding places. "I can live with that part of the drought," said Scott Trout as he left a playground in Westwood, Kansas, with his wife and two children. (Additional reporting by Timothy Gardner; Writing by Peter Bohan; Editing by Todd Eastham)

Loading Slideshow...
  • In this Dec. 28, 2012 photo, corn stalks stand in a snowy field near La Vista, Neb. Despite getting some big storms in December, much of the U.S. is still desperate for relief from the nation’s longest dry spell in decades. And experts say it will take an absurd amount of snow to ease the woes of farmers and ranchers. (AP Photo/Nati Harnik)

  • In this Dec. 28, 2012 photo, Bales of corn stalks are covered with a dusting of snow near La Vista, Neb. Despite getting some big storms in December, much of the U.S. is still desperate for relief from the nation’s longest dry spell in decades. And experts say it will take an absurd amount of snow to ease the woes of farmers and ranchers. (AP Photo/Nati Harnik)

  • Severe Drought Threatens Midwest Corn Crops

    PRINCETON, IN - JULY 17: Drought-damaged corn grows in a field on July 17, 2012 near Princeton, Indiana. The corn and soybean belt in the middle of the nation is experiencing one of the worst droughts in more than five decades. Indiana was the nation's fourth largest corn producer in 2011. (Photo by Scott Olson/Getty Images)

  • Severe Drought Threatens Midwest Corn Crops

    FRITCHTON, IN - JULY 17: Corn plants dry in a drought-stricken farm field on July 17, 2012 near Fritchton, Indiana. The corn and soybean belt in the middle of the nation is experiencing one of the worst droughts in more than five decades. Indiana was the nation's fourth largest corn producer in 2011. (Photo by Scott Olson/Getty Images)

  • In this July 26, 2012 photo, dead fish float in a drying pond near Rock Port, Mo., as a turkey vulture paces the shore. Multitudes of fish are dying in the Midwest as the sizzling summer dries up rivers and raises water temperatures in some spots to nearly 100 degrees. (AP Photo/Nati Harnik)

  • Severe Midwest Drought Continues

    WYATT, MO - JULY 18: A buoy used to help guide barges rests on the bank after the water level dropped on the Mississippi River July 18, 2012 near Wyatt, Missouri. Some barge operators have lightened their loads or stopped running altogether on the lower Mississippi because of low water levels. (Photo by Scott Olson/Getty Images)

  • Midwest Farmers Continue To Struggle Against Extended Drought

    CUBA, IL - AUGUST 03: Grass, dried from heat and drought, struggles to survive in a cattle pasture August 3, 2012 near Cuba, Illinois. Cattle being raised in the pasture used to be self-sustaining. This summer's drought has forced the farmer to truck in water, after the pond dried up, and extra feed, to supplement the dry grass, from another farm nearly 20 miles away. Farmers in the Midwest and elsewhere continue to struggle after than half the counties in the United States have been designated disaster areas, mostly due to drought conditions throughout the Midwest. (Photo by Scott Olson/Getty Images)

  • Midwest Farmers Continue To Struggle Against Extended Drought

    NEW HARMONY, IN - AUGUST 03: Corn dead from drought sits in a field August 4, 2012 near New Harmony, Indiana. More than half of the counties in the United States have been designated disaster areas, mostly due to drought conditions throughout the Midwest. (Photo by Scott Olson/Getty Images)

  • The last remaining water in a drought-stricken rural pond reflects the sky and clouds near Calumet, Okla., Friday, July 20, 2012. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought. (AP Photo/Sue Ogrocki)

  • Cattle graze in a dry field near Calumet, Okla., Friday, July 20, 2012. (AP Photo/Sue Ogrocki)

  • Rows of corn stalks stand under a cloudless sky south of Blair, Neb., Monday, July 23, 2012. The drought-damaged field was cut down for silage. (AP Photo/Nati Harnik)

  • Central Illinois cattle stand in a pasture struggling from lack of rain and a heat wave covering most of the country, Friday, July 20, 2012, in Farmingdale, Ill. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought, and most of the rest is abnormally dry. (AP Photo/Seth Perlman)

  • In this July 19, 2012 photo, a herd of cattle belonging to Kendal Grecian drink from a water tank at his ranch in Palco, Kan. Grecian spent years meticulously breeding his cows to improve the genetics in each generation, but with Kansas in one of the worst droughts seen in decades, he's struggling to find enough grazing to feed 300 cows, plus their calves. He hopes to get by with selling only a quarter of his herd, but there are no guarantees with the drought expected to linger through October. (AP Photo/John L. Mone)

  • A field of corn withers under triple-degree heat north of Wichita, Kan., in Sedgwick County Monday, July 16, 2012. The drought gripping the United States is the widest since 1956, according to new data released Monday by the National Oceanic and Atmospheric Administration. Fifty-five percent of the continental U.S. was in a moderate to extreme drought by the end of June, NOAA's National Climatic Data Center in Asheville, N.C., said in its monthly State of the Climate drought report. That's the largest percentage since December 1956, when 58 percent of the country was covered by drought. (AP Photo/The Wichita Eagle, Mike Hutmacher)

  • Boats sit on the bottom in a dry cove at Morse Reservoir in Noblesville, Ind., Monday, July 16, 2012. The reservoir is down nearly 6 feet from normal levels and being lowered 1 foot every five days to provide water for Indianapolis. (AP Photo/Michael Conroy)

  • A Great White Egret looks for food on a lake drying up from lack of rain Saturday, July 21, 2012 in Chandlerville, Ill. Wildlife as well as livestock, and crops are struggling from the dry weather and a heat wave covering most of the country. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought, and most of the rest is abnormally dry. (AP Photo/Seth Perlman)

  • Boats sit on the dry, cracked bottom in a dry cove at Morse Reservoir in Noblesville, Ind., Monday, July 16, 2012. The reservoir is down nearly 6 feet from normal levels and being lowered 1 foot every five days to provide water for Indianapolis. (AP Photo/Michael Conroy)

  • A cow looks for something to eat as it grazes in a dry pasture southwest of Hays, Kan., in a July 6, 2012 photo. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought, and most of the rest is abnormally dry. (AP Photo/The Hays Daily News, Steven Hausler)

  • Corn stalks struggling from lack of rain and a heat wave covering most of the country lie flat on the ground Monday, July 16, 2012, in Farmingdale, Ill. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought, and most of the rest is abnormally dry. (AP Photo/Seth Perlman)

  • The gate is closed on a boat ramp leading to a dry cove at Morse Reservoir in Noblesville, Ind., Monday, July 16, 2012. The reservoir is down nearly 6 feet from normal levels and being lowered 1 foot every five days to provide water for Indianapolis. (AP Photo/Michael Conroy)

  • Farmer Joe Fischer holds ears of corn showing the variety of kernal development Thursday, July 12, 2012, at Fischer Farms Inc. in Owensboro, Ky. Normally the silks would already be brown, Fischer said. "There is no pollen left because the silks were delayed. . . because it has been too hot and dry," Fischer said. All five Owensboro-area counties have been designated primary disaster areas because of drought. (AP Photo/The Messenger-Inquirer, John Dunham)

  • Devin Davis of Paul Tree Farms uses a special water canon to water 30,000 trees on the 60 acre farm Saturday, July 21, 2012 in Pleasant Plains, Ill. The trees as well as livestock, wildlife and crops are struggling from lack of rain and a heat wave covering most of the country. The nation's widest drought in decades is spreading. More than half of the continental U.S. is now in some stage of drought, and most of the rest is abnormally dry. (AP Photo/Seth Perlman)

  • A pontoon is anchored on a mud flat as the owner could not reach their dock at Morse Reservoir in Noblesville, Ind., Monday, July 16, 2012. The reservoir is down nearly 6 feet from normal levels and being lowered 1 foot every five days to provide water for Indianapolis. (AP Photo/Michael Conroy)

  • This Thursday, July 5, 2012 photo shows dry soil in a corn field in western Kentucky. Persisting drought conditions have endangered corn fields in western Kentucky. (AP Photo/The Paducah Sun, Allie Douglass)

  • Illinois Farms Hurt By Continued Midwest Drought

    OLMSTED, IL - JULY 26: A corn plant grows in a field parched by drought on July 26, 2012 near Olmsted, Illinois. The field, farmed by Kevin Ulrich, was one of several in the drought stricken region of Southern Illinois that were visited by officials from the United States Department of Agriculture's (USDA) Farm and Foreign Agriculture Services (FFAS) department and Farm Service Agency (FSA). Seventy percent of Illinois, the nation's number two corn producing state, is classified as experiencing some level of drought.(Photo by Scott Olson/Getty Images)

  • Burnt stalks lie on the ground among rows of corn damaged by drought in a parched field in Louisville, Ill. on Monday, July 16, 2012. Over ten days of triple digit temperatures with little rain in the past two months is forcing many farmers to call 2012 a total loss. Rows of corn sit under high temperatures, burning and crisping until the stalks eventually fall, burning into the dry soil. (AP Photo/Robert Ray)

  • Four rows of corn left for insurance adjusters to examine are all that remain of a 40-acre cornfield in Geff, Ill. that was mowed down Monday, July 16, 2012. Over ten days of triple digit temperatures with little rain in the past two months is forcing many farmers to call 2012 a total loss. (AP Photo/Robert Ray)

  • Jack Maloney checks on corn on his farm in Brownsburg, Ind., Monday, July 16, 2012. With no significant rainfall since May 3 and the bleak outlook for rain, Maloney expects a total loss on his corn and soybean crop. (AP Photo/Michael Conroy)

  • A dry field of corn is seen near Fremont, Neb., Monday, July 16, 2012. The drought gripping the United States is the widest since 1956, according to new data released by the National Oceanic and Atmospheric Administration. (AP Photo/Nati Harnik)

  • Jack Maloney displays a drought-damaged ear of corn on his farm in Brownsburg, Ind., Monday, July 16, 2012. With no significant rainfall since May 3 and the bleak outlook for rain, Maloney expects a total loss on his corn and soybean crop. (AP Photo/Michael Conroy)

  • An empty dock sits on the bottom of a dry cove at Morse Reservoir in Noblesville, Ind., Monday, July 16, 2012. The reservoir is down nearly 6 feet from normal levels and being lowered 1 foot every five days to provide water for Indianapolis. (AP Photo/Michael Conroy)

  • Leaves become dry and brittle on stalks of corn in a parched field outside Effingham, Ill., Monday, July 16, 2012. The drought gripping the United States is the widest since 1956, according to new data released Monday by the National Oceanic and Atmospheric Administration. This summer, 80 percent of the U.S. is abnormally dry, and the report said the drought expanded in the West, Great Plains and Midwest last month with the 14th warmest and 10th driest June on record. (AP Photo/Robert Ray)

  • A dry field of corn is seen near Fremont, Neb., Monday, July 16, 2012. The drought gripping the United States is the widest since 1956, according to new data released by the National Oceanic and Atmospheric Administration. (AP Photo/Nati Harnik)

  • The sun rises Sunday, July 15, 2012, in Pleasant Plains, Ill. Corn stalks are struggling in the heat and continuing drought that has overcome most of the country. All of Illinois is officially in a drought, and Illinois Gov. Pat Quinn plans a trip to southern Illinois to discuss the state's plans for responding to dry conditions. (AP Photo/Seth Perlman)

  • Joe Fischer checks on his corn field Thursday, July 12, 2012, at Fischer Farms Inc. in the 3700 block of Fisher Road in Owensboro, Ky. "We've been in a drought for the last three weeks," he said. Fischer farms the property with his brother Tony Fischer. They planted 900 acres of corn with 30,000 plants per acre. "We have no idea what our yield will be," Joe Fischer said. U.S. Agriculture Secretary Tom Vilsack has designated 26 Kentucky counties among more than 900 counties in 29 states as disaster areas. (AP Photo/Messenger-Inquirer, John Dunham)

  • In this photo taken June 27, 2012, farm worker Juan Carlos walks to an irrigated soybean field near England, Ark. The U.S. Agriculture Department has granted a disaster declaration for 69 of Arkansas' 75 counties due to the drought. (AP Photo/Danny Johnston)

  • Midwest Farmers Continue To Struggle Against Extended Drought

    CUBA, IL - AUGUST 03: Cattle try to keep cool in the remains of a farm pond in a pasture heavily damaged by drought August 3, 2012 near Cuba, Illinois. Farmers in the Midwest and elsewhere continue to struggle after than half the counties in the United States have been designated disaster areas, mostly due to drought conditions throughout the Midwest. (Photo by Scott Olson/Getty Images)

  • Midwest Farmers Continue To Struggle Against Extended Drought

    CUBA, IL - AUGUST 03: Cattle nibble the remains of grass in a pasture heavily damaged by drought August 3, 2012 near Cuba, Illinois. Farmers in the Midwest and elsewhere continue to struggle after than half the counties in the United States have been designated disaster areas, mostly due to drought conditions throughout the Midwest. (Photo by Scott Olson/Getty Images)

  • Steve Niedbalski chops down his drought and heat stricken corn for feed Wednesday, July 11, 2012 in Nashville Ill. Farmers in parts of the Midwest are dealing with the worst drought in nearly 25 years. (AP Photo/Seth Perlman)

  • Illinois Gov. Pat Quinn, second left, peels away the husk of a drought-ravaged ear of corn, only to find it had no kernels, as Illinois Farm Bureau President Philip Nelson, right, looks on during visit to the Laird Family Farm in Waltonville, Ill. on Monday, July 16, 2012. Quinn says the state will offer an array of debt restructuring and loan programs to farmers and ranchers affected by the drought. Drought is affecting much of the Midwest, where almost a third of the nation's corn crop has been damaged by heat and drought so severe that some farmers have cut down crops midway through the growing season. (AP Photo/Jim Suhr)

  • Also On The Huffington Post...

    A devastating drought in southwestern China's Yunnan province is entering its third year.

  • Severe Midwest Drought Continues

    WYATT, MO - JULY 18: Corn plants struggle to survive in a drought-stricken farm field on July 18, 2012 near Wyatt, Missouri. The corn and soybean belt in the middle of the nation is experiencing one of the worst droughts in more than five decades. All 114 of Missouri's counties have received disaster designations because of drought. Last year this area, which sits across the Mississippi River from Illinois, was ravaged by flooding after the Army Corps of Engineers blasted a hole in a levee to save the town of Cairo, Illinois from the rising Mississippi. (Photo by Scott Olson/Getty Images)

  • Severe Midwest Drought Continues

    VINCENNES, IN - JULY 18: Corn plants struggle to survive in a drought-stricken farm field on July 18, 2012 near Vincennes, Indiana. The corn and soybean belt in the middle of the nation is experiencing one of the worst droughts in more than five decades. Indiana was the nation's fourth largest corn producer in 2011. (Photo by Scott Olson/Getty Images)

  • In this July 26, 2012 photo, dead fish decompose in a drying pond near Rock Port, Mo. Multitudes of fish are dying in the Midwest as the sizzling summer dries up rivers and raises water temperatures in some spots to nearly 100 degrees. (AP Photo/Nati Harnik)

  • This photo from July 31, 2012 shows a beached air boat as bathers walk in the nearly dry Platte River near Yutan, Neb., Tuesday, July 31, 2012. The latest U.S. Drought Monitor survey shows an increase in extreme drought conditions in four Plains states but a slight decrease in the overall area of the lower 48 states experiencing some form of drought. (AP Photo/Nati Harnik)