On July 21, 1998, at 0715 hours Pacific daylight time, an Ayers S2R, N8960Q, collided with an irrigation standpipe while maneuvering to spray crops near Shafter, California. The aircraft, operated by Inland Crop Dusters, Inc., under 14 CFR Part 137 as an agricultural crop dusting flight, sustained substantial damage. The commercial pilot was not injured. Visual meteorological conditions existed for the flight and no flight plan was filed. The pilot stated that no discrepancies were noted with the takeoff or with crop dusting flight. On the last pass of the morning on an easterly heading, the pilot stated that he spotted a standpipe and attempted to avoid it by pulling the aircraft up. He stated that the airplane collided with the standpipe and he made an emergency landing. During the landing roll, the airplane nosed over in soft soil. The pilot stated that the emergency landing was conducted with the standpipe attached to his left main inboard wing. The pilot reported that no mechanical anomalies were noted with the aircraft or engine. In an interview with a Federal Aviation Administration (FAA) inspector the pilot stated that on the last pass, the sun had risen and was reflecting off a clear plastic crop cover. The pilot stated that it made it difficult to see the standpipe, and when he did see it he was too close to avoid it and impacted it. According to a computer generated Sun/Moon astrological program, the magnetic bearing to the sun was 60.7 degrees, and it was approximately 14.4 degrees above the horizon.