The airplane was departing from a 2,400-foot asphalt runway on an aerial application flight. The airplane was loaded to its maximum gross takeoff weight and configured with 10 degrees of flaps prior to the takeoff roll. The pilot reported that a tall stand of trees at the southeast side of the departure end of the runway blocked the wind and seemed to “create a void in the air,” which resulted in an extended takeoff roll. Electing not to abort the takeoff, the pilot added more flaps in an attempt to get the airplane airborne; however, he was unsuccessful. The airplane went off the end of the runway, hit a ditch, and skidded across the road into a field. The landing gear separated from the airframe and the airplane’s fuselage and control surfaces sustained substantial damage. The pilot reported that there were no mechanical malfunctions or failures that would have precluded normal operation during the attempted takeoff.