Grasshopper Armyworm damage (GAW)

Description

Kernels of wheat that are damaged by grasshopper or armyworm are chewed, usually on the sides, as defined in the wheat section of the Official Grain Grading Guide.

Procedure for assessment

Grasshopper or armyworm damaged are considered an objective grading factor with assigned percentages in each grade. To assess grasshopper or army worm damaged kernels, the inspector performs a physical separation to assess the percentage of these damaged kernels in the sample. The number of grams utilized to perform the assessment is predetermined and defined in the Official Grain Grading Guide. The inspector will then apply the tolerances as set out in the Grade Determinant Tables found in the Official Grain Grading Guide.

Care must be taken not to confuse kernels damaged by grasshopper or army worms with broken kernels. 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, as defined in the wheat section of the Official Grain Grading Guide.

Cause

Grasshoppers and armyworms chew out sections of kernels, particularly the ends and sides. At an early stage, armyworms may chew tunnels through the kernels.

End-use issues

This damage destroys the endosperm, and leaves the exposed chewed areas susceptible to fungal and bacterial infections. Heavy discolourations and moulds may result.

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