Immediately after takeoff, but before beginning his initial climb, the pilot of the loaded aerial application airplane remained in ground effect to verify his instruments. After confirming that the RPM and manifold pressure were within limits, he tried to initiate his after takeoff climb. At that point he noticed that he had no climb performance, and elected to make a forced landing straight ahead off the end of the runway before reaching the end of the airport property. During the forced landing, the airplane’s right wing struck the ground, resulting in substantial damage to its structure. Examination of the engine by a Federal Aviation Administration inspector revealed that the number one cylinder air induction tube had become disconnected from the induction air manifold. The clamp on the tube was still in place, and there had been no recent maintenance associated with the induction system. The reason for the separation of the tube could not be determined.