Wheat: Grading factors

Artificial stain (ART STND)

Artificial stain

• Includes any nontoxic stain on kernels caused by contact with foreign substances such as dye, oil, grease, paint, or soot
• Does not include any stain considered a natural stain
• Does not include any stain caused by coming into contact with poisonous substances, or any stain that could be considered Contaminated grain

Binburnt kernels (BBT)

Binburnt kernels are blackened as a result of severe heating in storage. A cross section of a binburnt kernel maintains its dense structure and appears smooth and glossy. A binburnt kernel is similar in weight to sound kernel.There is a single tolerance for the total of binburnt, severely mildewed, mouldy, and rotted kernels.

Blackpoint (BLK PT)

Kernels with blackpoint have a distinct dark brown or black discolouration of the whole germ and surrounding area.

Broken (BKN)

Broken kernels are pieces of wheat that are less than three-quarters of a whole kernel. If the piece is more than three-quarters of a kernel, it is considered whole. See Shrunken and broken.

Common bunt (stinking smut) (SMUT)

Common bunt is a plant disease caused by fungi, characterized by

• Soft black bunt balls
• Kernels tagged with black bunt spores
• A distinct smutty odour, or the smell of rotten fish

Contaminated grain

Grain is contaminated for the purposes of the Canada Grain Act if the grain contains any substance in sufficient quantity that the grain is either

1. adulterated for the purposes of the Food and Drugs Act; or 
2. contaminated within the meaning of the regulations made under section 51 of the Safe Foods for Canadians Act.

Contrasting classes (CON CL)

See Wheats of other classes or varieties (WOOC)

Dark immature kernels (DKIM)

Dark immature kernels are also called swath-heated kernels. They are similar to heated kernels, but they do not exhibit the reddish discolouration associated with heated kernels, and they do not have a heated odour.

• Are considered as damage for grading purposes in CWRW

Degermed kernels (DGM)

The germ has been removed through the mechanical handling process or by insect attack. Degermed kernels lack the greyish discolouration that is often present with sprouted kernels.

• Are considered as damage for grading purposes in CWRW.
  See Insect damage
  See See Sprouted and Severely sprouted kernels.

Earth pellets

• Hard earth pellets are pellets that do not crumble under light pressure. See Stones.
• Soft earth pellets are pellets that crumble under light pressure. See Soft earth pellets.

Ergot (ERG)

Ergot is a plant disease producing elongated fungus bodies with a purplish-black exterior, a purplish-white to off-white interior, and a relatively smooth surface texture.

Excreta (EXCR)

Excrement from any animal including mammals, birds and insects.

Extraneous material

Can be defined as glass, metal, wood, plastic or any other material not already defined in the Official Grain Grading Guide.

Fertilizer pellets (FERT PLTS)

Fertilizer pellets are a manufactured plant nutrient product used by producers in the production of grain. They are typically small, round or irregular shaped and usually white, grey, brown, pink or reddish in colour.

Fireburnt (FBNT)

Fireburnt kernels are charred or scorched by fire. A cross-section of a fireburnt kernel resembles charcoal with numerous air holes. The air holes result in a low-weight kernel which crumbles easily under pressure.

Foreign material (FM)

Foreign material is anything that is not wheat that remains in the sample after the removal of dockage.

Frost (FR)

Frost refers to wheat kernels with blistered brans as a result of exposure to freezing temperatures. The degree of blistering ranges from fine to coarse and is dependent upon the maturity of the grain, the temperature to which the grain was exposed and the duration of the exposure. Samples containing kernels affected by Frost are graded according to the degree of soundness definition as reflected in the standard prints for each grade. Standard prints are not available for all classes of wheat; refer to the table below to determine the applicable standard for a sample class.

Fusarium damage (FUS DMG)

Fusarium-damaged wheat is typically characterized by thin or shrunken chalk-like kernels. Fusarium-damaged kernels have a white or pinkish mould or fibrous growth.

Grass green kernels (GRASS GR)

Grass-green kernels are a distinct vivid green throughout because of immaturity.

• Are considered as damage for grading purposes in CWRW

Green (GR)

Green wheat kernels may range from fully developed to shrunken and distorted with various degrees of darkening that are in contrast to the natural sound colour. The maturation process has been affected or arrested by the environment or an agronomic practice resulting in a variation in colour, size and shape. The physical effect is dependent on the timing and extent of the exposure to the contributing factors.

Dark immature, Grass green and Immature are separate grading factors that should not be confused with Green damaged kernels.

Samples containing Green kernels are graded according to the degree of soundness definition as reflected in the standard or guide samples for each grade.

Hail damage (H DMG)

Hail damage is visually similar to sawfly damage. Hail damaged kernels are considered as Sawfly damage for grading purposes.
See Sawfly damage.

Hard vitreous kernels (HVK)

Vitreousness is the natural translucence of a kernel that is a visible sign of kernel hardness. Hard vitreous kernels (HVK) are a grade determinant for the amber durum wheat class in Canada and the red spring wheat class in western Canada.

Heat stress (HTS)

Heat stress refers to wheat kernels with blistered brans as a result of exposure to prolonged hot weather conditions. The degree of blistering ranges from fine to moderate and is dependent upon the maturity of the grain, the temperature to which the grain is exposed and the duration of the exposure. Heat stressed kernels may be visually indistinguishable from Frost affected kernels, but rarely exhibit severe blistering or distortion. Samples containing kernels affected by Heat stress are graded according to the degree of soundness definition and the Frost standard prints for each grade.
See Frost

Heated kernels (HTD)

Heated kernels have the colour and may have the odour typical of grain that has deteriorated in storage or has been damaged by artificial drying. They range from orange-red to very dark brown, but are not black. Heated seeds of other grains are included in the tolerance for Heated.

Immature (IM)

Immature wheat kernels are not fully ripened. The kernels may be fully developed with various shades of green that are in contrast to the natural sound colour. The kernel development has been arrested during the maturation process often resulting in variation in colour, size and shape.

Dark immature and Grass green are separate grading factors that should not be confused with Immature kernels.

Samples containing Immature kernels are graded according to the degree of soundness definition as reflected in the standard samples for each grade.

Insect damage (I DMG)

Insect damaged kernels have been bored or chewed by insects resulting in a portion of the endosperm being removed. Insect damage is characterized by chew and bite marks or by small holes drilled into the sides or germ area of the kernel. Damage can be caused by field insects such as grasshoppers or armyworms, as well as stored grain pests such as the Indian meal moth, red flour beetle or the lesser grain borer.

Midge damaged kernels are not considered insect damaged and are assessed separately. See Midge Damage

Surface damage, where only small portions of the bran have been removed, should not be considered damaged but should be considered in the degree of soundness

• Are considered as damage for grading purposes in CWRW

Matter other than cereal grains (MOTCG)

Matter other than cereal grains is

• Inseparable seeds such as ragweed, Tartary buckwheat, rye grass, and wild oats
• Non-cereal domestic grains such as canola, flaxseed, corn, peas, buckwheat and lentils that remain in the cleaned sample

Midge damage and Severe midge damage (MDGE, SEVMDGE)

The tolerance for sawfly damage and midge damage is combined. The damaged kernels are weighed together and a percentage determined. This percentage is then compared to the Grade Determinant table to assign the appropriate grade.

Mildew (MIL)

Mildew kernels are kernels affected by field fungi that develop under conditions of excessive moisture affecting unthreshed kernels of wheat. Samples affected by mildew have an overall greyish discolouration with grey to black mildew spores typically attached to the brush end of the kernel.

Samples containing kernels affected by mildew are graded according to the degree of soundness definition as reflected in the standard samples for each grade. Standard samples are not available for all classes of wheat; refer to the table below to determine the applicable standard for a sample class.

See Severely mildewed for heavily affected samples

Mineral matter (MIN MAT)

Mineral matter refers to stones, earth pellets, fertilizer and screening pellets that may be found in samples of grain.

Mouldy kernels (MLDY KRNL)

Mouldy kernels are discoloured, swollen and soft as a result of decomposition by fungi or bacteria. They have mould visible to the naked eye and may feel spongy under pressure

There is a single tolerance for the total of binburnt, severely mildewed, mouldy, and rotted kernels.

Natural stain (NSTN)

Naturally stained kernels are caused by contact with natural substances such as bunt spores, soil or weeds. Consideration is given to the incidence of affected kernels and the nature and severity of the stain. Kernels that are lightly stained should not be considered.

When the nature of the material is in doubt, the sample is sent to the Chief Grain Inspector for review, and, if necessary, for laboratory analysis.

See Glossary, weed stain

Odour (ODOR)

There is no numeric tolerance for odour. Consider

• The basic quality of the sample
• The type and degree of the odour—such as fuel oil, skunk or urea
• The presence of visible residue causing the odour

Other cereal grains (OCG)

Other cereal grains in wheat are rye, barley, triticale, oats, oat groats, and wild oat groats that remain in the cleaned sample. Other cereal grains are treated as total foreign material.

For grading purposes, spelt and Kamut® are considered as Other cereal grains in samples of wheat.

Penetrated smudge (PENT SM)

With penetrated smudge, the discolouration penetrates and extends throughout the endosperm, usually as a result of a more severe infection.

Note: Cutting of kernels is permitted

Pink kernels (PNK)

Pink pigment in wheat kernels is an indication of immaturity. Pink kernels

• Are shrunken
• Display a pink discolouration
• Are considered as damage for grading purposes in CWRW

Protein (PROT)

The classes of CWRS, CWHWS, CWAD, CNHR, CWES and CWRW wheat have minimum protein levels established for numberNo. 1 grades. Protein content is reported on a 13.5% moisture basis.

See Primary grade determinants tables.

Rotted kernels (ROT KRNL)

Rotted kernels are discoloured, swollen and soft as a result of decomposition by fungi or bacteria. They may feel spongy under pressure.

There is a single tolerance for the total of binburnt, severely mildewed, mouldy, and rotted kernels.

Ruptured kernels

Kernels are considered to be ruptured when the split in the cheek extends at least half the length of the cheek or if both cheeks are split to any degree. Ruptured kernels do not require magnification to be identified.

Ruptured kernels are considered as severely damaged and are assessed using the degree of soundness definition in the grading table.

Sclerotinia sclerotiorum (SCL)

Sclerotinia sclerotiorum is a fungus producing hard masses of fungal tissue, called sclerotia. The sclerotia vary in size and shape, have a course surface texture, vary in exterior color from dark black to gray to white and have a pure white interior.

Severely damaged kernels

Kernels are considered to be severely damaged when

• the kernel is severely shriveled or distorted due to weather, insect, fungal and/or other reason
• in wheat, the cheeks and/or back of the kernel are ruptured

Severely midge damaged kernels (SEVMDGE)

See Midge damage and Severe midge damage

Severely mildewed kernels (SEVMIL)

In severely mildewed wheat, mildew spores have severely blackened the kernel inside and out. The kernels may feel spongy under pressure.

There is a single tolerance for the total of binburnt, severely mildewed, mouldy, and rotted kernels.

Severely sprouted kernels (SEVSPTD)

See See Sprouted and Severely sprouted kernels

Shrunken and broken (SHR, BKN)

Percentages of shrunken and broken kernels are determined from the same representative portion.

Smudge (SM)

Smudge is a discolouration on the kernel as a result of infection by some common field fungi. The discolouration may be brown, black or red.

Soft earth pellets (SEP)

Soft earth pellets are

• Earth pellets that crumble into fine dust under light pressure, using a finger only— if they do not crumble, they are considered Stones.
• Any nontoxic material of similar consistency.

Sprouted and Severely sprouted kernels (SPTD, SEVSPTD)

Sprouted kernels (SPTD)

Kernels are assessed as sprouted if one of the following conditions exists:

Stones (STNS)

Stones are hard shale, coal, hard earth pellets, and any other nontoxic materials of similar consistency. Fertilizer pellets are assessed as stones when constituting 1.0% or less of the net sample weight. (See Fertilizer pellets for specific procedures to be followed when samples contain fertilizer pellets.)

Streak mould

Kernels with unusual dark grey streaks on their sides toward the brush may indicate streak mould. This very slow-growing mould is harmless in wheat, but it affects kernel appearance. It occurs most commonly in red winter wheat. It is not related to the more serious storage moulds.

Superficial discolouration (SUPDISCLR)

Superficial discolouration is a reddish discolouration not penetrating the endosperm. This factor is evaluated subjectively in relation to the degree of soundness without reference to specific tolerances.

Test weight (TWT)

Test weight is the weight of a known volume of grain expressed in kilograms per hectolitre. For procedures, see Chapter 1 of this guide, Test weight.

Total damage (TDMG)

Includes kernels that are dark immature, degermed, fireburnt, fusarium damaged, grass green, heated, insect damaged, pink, sawfly/midge damaged, smudge damaged, sprouted or damaged in any other way.

Treated seed and other chemical substances

Wheats of other classes or varieties (WOOC)

• Other classes of wheat are all classes of wheat, including non-registered varieties, other than the predominant class in the sample.
• Contrasting classes are classes of different colour wheat; for example, CWAD is a contrasting class in CWRS.
• Other varieties of wheat are any registered varieties.