* Some Indiana corn fields likely to yield no grain
* Indiana yield at 4 sites at 56.3 bpa, vs 143.4 year ago
* Yield in 7 Illinois fields at 109.7, vs 153.2 in 2011
* Soybeans need rain soon or pods may begin aborting (Updates with final day 2 data, adds details, changes dateline, previously DANVILLE, Ill.)
By Karl Plume
BLOOMINGTON, Ill., July 24 (Reuters) - On the western edge of Indiana, the Putnam County corn crop shows the effects of the worst U.S. drought in 56 years: the plants failed to form ears and will likely go unharvested, the second day of a U.S. Midwest crop tour found on Tuesday.
The area has so far received none to just a quarter of its normal rainfall since the beginning of June while temperatures have consistently soared above 100 degrees Fahrenheit. Because of the heat and dry conditions, plants are stunted at around 3 feet, leaves are curled and brown at the edges and stalks are brown at the bottom.
Most likely, the plants are dying.
Crop scouts on the five-day MDA EarthSat July Crop Tour did not stop to inspect the fields because crops were so poor it was assumed that farmers will plow them under and, if they have it, collect crop insurance.
The average corn yield in Putnam County last year was 142.4 bushels per acre, according to the U.S. Agriculture Department.
Fields showed few signs of improvement as the tour moved into eastern Illinois, the No. 2 corn growing state after Iowa. Plants were stunted and dry, with leaves curled tightly in self defense from scorching afternoon temperatures in the high 90s.
John Schlipf, who farms corn and soybeans on 600 acres in Livingston and McLean counties, said his crops received just three-tenths of an inch of rain so far this month while temperatures have regularly soared above 100 degrees.
The corn yield in one of his more productive fields was estimated at about 117 bushels per acre (bpa), down sharply from the 206 bpa he reaped last summer from an adjacent field which he seeded with soybeans this year. Another nearby field, he said, may yield no more than 10 or 20 bushels per acre.
"This is worse than 1988, but we're looking at better corn now, better genetics. This is the first drought since BT3 corn," he said, referring to the genetically engineered corn that was not available a quarter century ago.
In neighboring Champaign county, the tour surveyed one field with no formed ears which was likely to go unharvested. Another field ten miles away in the same county had 188 bpa, the most promising yield prospects the tour had seen far.
Crops were variable across the region, the result of prolonged periods of high heat and moisture stress.
"Inconsistent field averages along with small ears and low kernel production will ultimately lead to lower yields than currently estimated," said Matt Guth, a futures and options specialist with RCM Asset Management who was on the tour.
"On top of this we have seen entire fields that have died out with some receiving less than a half inch of rain since May," he added.
Surveys of four corn fields in west central Indiana found an average of just 56.3 bushels per acre in Hendricks, Putnam, Parke and Vermillion counties. That was down sharply from an average of about 143.4 bpa for the area in 2011.
Average yields in seven Illinois corn fields in Edgar, Vermillion, Champaign, Ford, Livingston and McLean counties were 109.7 bushels per acre, well below an average of 153.2 bpa for the area last year.
The corn crop in both states was rated only 7 percent good to excellent as of Sunday, down 1 percentage point from the previous week in Indiana and down 4 points in Illinois, USDA reported.
The tour does not project soybean yields but the soy plants in many fields were standing up better to the dry conditions, their leaves turning over for protection during the day's heat. But the crop will need rain soon or the pods that have been set could begin to abort.
The tour started in Columbus, Ohio, on Monday and will finish in Omaha, Nebraska, on Friday.
Drought led the USDA to slash its estimate of the U.S. corn yield estimate by an unprecedented 20 bushels per acre in July. It is expected to cut it further when it releases its August crop report, which will be based on a survey of farmers.
Analysts expect the USDA's August crop report to show that millions of acres of damaged crops will not be harvested this year, allowing farmers to collect on crop insurance.
The decline in the U.S. corn and soybean crops has rallied prices to record highs at the Chicago Board of Trade, although rain this week in the northern and eastern reaches of the Midwest has trimmed some of the gains.
In Indiana's Parke County, the corn crop was also in poor condition but somewhat better than in neighboring Putnam County.
Plants were 4 to 5 feet tall, and only about 50 percent of the fields scouted in the area had no ears. But the crop showed signs of drought damage: leaves were curled and brown and the fields were pale green instead of the usual healthy dark green.
The stalks were brown half way up, a condition called 'firing' in farming parlance. The plants were poorly pollinated, with the ears not forming kernels all the way to the tip or all the way around the cob.
Calculations based on inspections of fields in Parke County put the average corn yield at 121 bushels per acre, down from the USDA's estimate last year of 148.6 bushels.
"This ground where they were looking, on a good year, is 200 bushel-plus," said Stewart Major, who has farmed 2,700 acres of corn and soybeans for six years in Parke County. "It started losing yield around the first of July when it started to tassel. There's 30,000 stand out there and only 20,000 have an ear now."
"We got a little rain in the last week and it's keeping some of it green. It seems to have helped but there's 10,000 plants out there with no ear on them." (Reporting by Karl Plume, additional reporting by Michael Hirtzer, writing by K.T. Arasu; editing by Jim Marshall and Miral Fahmy)