A device is described for introducing variation in athletic training and competitive events. Associated with each of mowing and take-in device is a conveyor for receiving and conveying plant parts, especially corn ears, possibly separated from the plants, and return devices for returning the plant parts into the plant stream conveyed in the header. A support system for the blades includes a support ring concentric with the turbine axis of rotation and adjacent to the peripheral boundary of the rotor. The syngas can be converted to alcohols, such as ethanol, or to other products.