2. Physical Tests

2.1. Dockage in Wheat
Dockage is seeds, weed stems, chaff, straw, sand, dirt, and any material other than the predominant grain which can be removed readily from the grain by use of sieves and cleaning devices. Elevators that do not accurately measure dockage lose money by paying grain price for non-grain material. In addition, the grading procedures for many grains, including wheat, triticale, sunflower seed, rye, flaxseed, and barley, specify that dockage must be removed before determining test weight. Elevator operators handling these grains that do not effectively remove dockage underestimate test weight and may assign incorrect grades.

2.2. Test Weight
Test weight is actually a measure of the density or weight per unit of volume of a grain at a standardized moisture level. In U.S. grain merchandizing channels this is typically expressed in pounds per bushel. Standards for test weight are set by the USDA Grain Inspection, Packers and Stockyards Administration (GIPSA). The following table gives minimum test weight standards for USDA quality grades in selected feed grains. Other factors such percentage of foreign material; broken kernels and heat damaged kernels can also alter the USDA quality grade. The complete set of grain quality standards can be found at the USDA GIPSA internet site www.usda.gov/gipsa/reference-library/standards/standards.htm.

Minimum Test Weight Standards (Lbs./Bushel) for USDA Grain Quality Grades

USDA Grade	Corn		Wheat*		Barley		Oats

1		56		60		47		36

2		54		58		45		33

3		52		56		43		30

4		49		54		40		27

5		46		51		36		-

* Includes all wheat types except hard red spring and white club wheat.