On June 6, 1998, at 1400 central daylight time, a Grumman G164, N710Y, while maneuvering at low altitude, encountered crops and impacted the terrain near Somonauk, Illinois. The pilot was not injured, however, the aircraft sustained substantial damage. The aircraft was being operated as an instructional flight under 14 CFR Part 91. The pilot was practicing aerial applications when the accident occurred. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated at Leland, Illinois, at 1300 In his written statement, the pilot said that he was making practice spray runs over a wheat field when the airplane, "caught a gust" of wind, got a wheel into the wheat, and he was unable to recover before the airplane impacted the terrain. A subsequent examination of the airplane failed to reveal any pre-accident anomalies which might have contributed to the accident.