This invention relates to a new herbicidal composition comprising desmedipham and optionally phenmedipham andor ethofumesate. The machine may have a controller in communication with an operator interface and a hydraulic system configured to control tracks of the machine. Tactile control signals may be provided to control operation of the transducers to guide motions of the student. The mutual authentication handshake of embodiments implements a protocol in which a session key is calculated by both nodes, thereby providing a secure means by which a cluster key may be shared. In one embodiment, the stator plate is configured to rotate and apply a skew condition to each of the planet axles.