The accident airplane collided with high vegetation and terrain after a premature liftoff during a takeoff ground run. A designated pilot examiner (DPE) was administering a private pilot flight test to a private pilot candidate. He requested the student pilot demonstrate a short field takeoff. According to the DPE, as the airplane proceeded down the runway it became apparent that the airplane was behind the power curve. He was about to pull the power when the airplane became airborne and made a turn to the left. The left wing hit corn at the side of the runway, pulling the airplane into the corn. The student pilot said he pulled the nose up as soon as possible and used side to side vision to steer the airplane. He said the ride seemed slow and rough. The airplane became airborne momentarily twice. When he spotted the corn he tried to pull up. The airplane lifted but settled back down at the edge of the corn.