On June 14, 1993, at approximately 1100 central daylight time an Ayres S2R T34, N3098W, near Weiner, Arkansas, sustained substantial damage during landing when the main gear collapsed. The commercial pilot did not sustain injury. Visual meteorological conditions prevailed for the local aerial application flight. During telephone interviews, conducted by the Federal Aviation Administration inspector and the investigator in charge with the operator and pilot, the following information was revealed. During the initial lift off from the runway, the airplane settled back onto the runway and the left main gear impacted a rice levee at the end of the runway. With the gear loose, the airplane maintained flight and the pilot continued the planned mission. After spraying the field, the pilot returned to the airstrip for landing. During the landing roll, on the terrain adjacent to the runway, control of the airplane was lost as both main gear folded under the wings. The airplane was released to the owner following the investigation.