On May 12, 1994, at approximately 1500 Pacific daylight time, N8214S, a Schweizer G-164B, sustained substantial damage, when during the initial climb after takeoff from a private farm airstrip near Yuba City, CA, the aircraft stalled and settled back to the ground approximately 400 yards from the runway end. The pilot was uninjured. There was no flight plan filed for the local agricultural application flight. Visual meteorological conditions prevailed at the time. The pilot stated the engine was running fine during the sequence. Wind conditions were described to be light and variable with no turbulence or gusts during a telephone interview. When he submitted his accident report, he indicated that winds were 5 knots from the south. The pilot reported that he had no idea of his actual gross takeoff weight, and stated that he was loaded with 2,800 pounds of the herbicide LONDAX. According to FAA documentation, maximum hopper capacity of this aircraft is 2000 pounds. The pilot made no turns after takeoff. The pilot had made 39 previous flights in the day but this was the first out of this particular airstrip.