The commercial certificated pilot reported that after liftoff on a Title 14, CFR Part 137 aerial application flight, he kept the airplane in ground effect to accelerate and clear wires at the end of the runway. He said the airplane would not climb high enough to clear the wires, and he elected to turn away from them. After initiating the turn, it became evident he could not turn quickly enough, and he decided to fly under the wires. While flying under the wires, the main landing gear wheels contacted mud, and the airplane nosed over, sustaining substantial damage to the wing. The pilot reported that he departed the gravel airstrip with about a 5 knot tailwind. Another pilot he spoke with said the tailwind increased to about 25 knots at the height of the wires (30 feet). The accident pilot stated that there were no preaccident mechanical problems with the airplane.