Graph 1 illustrates the relationship between percent Fusarium damaged kernels and percent weight. In order to use the graph, you must first examine your wheat sample for Fusarium damage. If you see any fungal growth on the seam or crease of the kernel that is often an indication of internal colonization of the seed by Fusarium. Through adjustments to the combine ground speed, fan speed and sieve settings you can reduce the number of infected kernels in your harvest sample and raise your seed grade. The easiest and best way to improve the grain sample is with proper combine adjustment.
Combines use air blast to separate grain from the chaff in a normal harvest operation.
As many of the fusarium infected kernels are small, shrunken and lighter than sound kernels, it is possible to blow a large proportion of these kernels out the back of the combine by increasing the air blast above normal ranges. In 1996 many producers operated combines at the maximium wind blast to increase grade. Another trick that helped some producers in 1996 was to reduce ground speed of the combine giving increased separation of the grain mass. This further allows the wind blast to separate the good kernels from the infected kernels. However, caution must be used to keep heads and straw particles out of the grain sample.