On March 4, 1994, at 1400 Pacific standard time, a Grumman G-164B, N6528K, sustained substantial structural damage during a downwind take off near Chico, California. The aircraft was owned and operated by Chico Aerial Applicators, Inc. of Chico, California, and was conducting an aerial application flight under 14 CFR Part 137. Visual meteorological conditions were prevalent at the time, and no flight plan was filed for the operation. The certificated commercial pilot was not injured. The flight originated on the day of the mishap at 0700 from the Chico Municipal Airport. In a verbal statement, the Federal Aviation Administration (FAA) inspector reported that the aircraft was loaded with fertilizer and was attempting a downwind takeoff from a private dirt agricultural airstrip. According to the inspector, the pilot said he was unable to maintain sufficient airspeed during his initial climb and the aircraft settled on rough terrain off the end of the strip, nosing over. In his written statement, the pilot reported that he had been instructed by the aircraft operator to use a power setting of 33 inches of manifold pressure and 1,800 rpm's. The pilot stated that these power settings were lower than the ones he had used the previous year and that the aircraft performance was more sluggish than in the past. At 1415, 190 gallons of ammonium sulfate was loaded in the hopper and 45 gallons of fuel was added. The pilot took off toward the south with an estimated tailwind of six knots. The pilot said he began a left turn toward a northeasterly direction, but noticed the aircraft was moving toward the south in a sideward drift. He also noticed that the aircraft was not climbing as expected, so he added one inch of manifold pressure and, as he did so, also noticed that the winds had increased. After the turn toward the northeast, the aircraft performance became even more sluggish and the aircraft began to settle. At the last moment, the pilot banked left to avoid a dirt embankment directly ahead of the aircraft, and stalled, contacting the ground in a dirt field. As the aircraft touched down, the propeller dug in and the aircraft nosed over.