Selected Physical Characteristics and Aerodynamic Properties of Cheat Seed for Separation from Wheat

Cheat and similar weeds infest wheat-producing areas throughout the world. Previous solutions to cheat control such as annual applications of herbicides, moldboard plowing to bury the seeds, burning wheat stubble, or rotation of summer crops have been only partially successful and most have adverse environmental effects. An alternative approach to cheat control is mechanically damaging cheat seed during harvest to prevent reinfestation in subsequent years. To design machines to separate cheat from wheat, physical characteristics (dimensions, weight, bulk density, shape) and aerodynamic properties (terminal velocity, drag coefficient) of cheat seed were determined and compared to those reported for wheat. Although cheat seeds are similar in length to wheat they are about 50% as thick, 13% as dense, and have 40% of the terminal velocity.