On June 15, 2005, at 0800 eastern daylight time, a Piper PA-25-260, N4754Y, operated by Wings Aerial Applicators, LLC. was substantially damaged during a forced landing while maneuvering near Southampton, New Jersey. The certificated airline transport pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local aerial application flight, conducted under 14 CFR Part 137. According to the pilot, he departed the Pemberton Airport (3N7), Pemberton, New Jersey at approximately 0725 hours for his second flight of the day. While applying liquid fungicide to a cranberry bog he passed over a road at 800 feet msl, and heard a "loud bang," quickly followed by a total loss of engine power. The pilot executed a 180-degree turn and maneuvered to align the airplane with the wind and a cornfield. He then dumped the 110-gallon, "dilute" load of fungicide and water over a field of sorghum. After clearing some trees, the airplane touched down firmly in a deeply furrowed cornfield with a steep uphill slope. The airplane then rolled out about 50 feet, the left main landing gear collapsed, and the airplane came to rest in an upright position. A visual examination of the engine by a Federal Aviation Administration (FAA) inspector, revealed an approximately 8-inch by 12-inch hole in the engine case, above the No. 4 cylinder in the area of the valve lifters. Further examination also revealed that the external damage extended down from the upper mating surfaces of the engine case to the top of the cylinder mounting pad. Internal examination of the engine revealed that the No. 1 cylinder connecting rod and bearings exhibited galling of the bearing, and crankshaft bearing surfaces. The No. 3 cylinder barrel skirt was damaged and exhibited indentations and local plastic yielding in several locations. Both the Nos. 4 and 5 cylinder connecting rods were broken and the Nos. 1, 2, and 4 cylinder connecting rod end caps, exhibited signs of heat stress. According to an FAA inspector, excessive galling of the bearing and crankshaft bearing surfaces were indicative of a "lack of lubrication," however; no mechanical malfunction, leak, or blockage of the lubrication system was reported by the inspector.