* Yield potential better but drought stressing crop
* Crop tour moves into Iowa later Wednesday
By Karl Plume
CANTON, Ill., July 25 (Reuters) - The corn crop in two counties in central Illinois showed yield potential better than last year despite the worst drought in decades in the U.S. Midwest, scouts on a crop tour reported on Wednesday.
It was the first time since the tour began in Ohio on Monday that scouts had come across fields where the yields were above those of a year ago.
In Logan County, corn yields were estimated at 197.9 bushels per acre, above last year's 173.4 bpa. In Sangamon County, the yield was an estimated 171.1 bpa, compared with 165.7 bpa last year, the tour found.
In neighboring Menard County, however, the yield was an estimated 132.8 bpa, down from last year's 168.4 bpa.
Illinois in the No. 2 corn growing state behind Iowa.
Scouts saw plants as tall as 9 feet (2.7 metres) in Logan County, and 6 to 7 feet high in Sangamon. The crops were planted early and likely escaped the high heat.
But the crops were beginning to show the typical signs of drought stress -- curled leaves and kernels not reaching the tip of the ears, known in industry parlance as "tip back."
The five-day MDA EarthSat crop tour moves into Iowa later on Wednesday, stopping overnight in Iowa City, before ending on Friday in Nebraska.
Chicago Board of Trade corn futures jumped more than 1 percent on worries that the most extensive U.S. drought since 1956 will reduce production. But prices remained below the record peak of $8.28-3/4 per bushel set last week. (Reporting by Karl Plume, writing by K.T. Arasu; Editing by Marguerita Choy)