Effects of moisture content of wheat on threshing

Authors: Harrison, H.P.
Description: Vas and Harrison (4) have defined the loss of grain associated with the cylinder of a combine as the sum of the damaged and unthreshed grain. The latter, but not the former, is readily assessed by the operator. Assessing damaged grain is complicated because it cannot be readily defined. It may vary from small cracks in the seed coat, which are invisible to the naked eye, to splitting of the kernel into two or more segments. Bacteria can enter the kernel through small cracks and thereby inhibit its viability and increase its tendency to mold when stored (2). It is evident that damaged kernels can be a loss even when they are not expelled with the chaff from the combine. Vas and Harrison (4) allege that an optimum cylinder speed exists with respect to the total grain loss. They found that the optimum cylinder speed was less than 800 rpm for the cultivar Park with a moisture content of 10% (wet basis, WB)a. Eight hundred rpm is less than the minimum cylinder speeds recommended by most combine manufacturers. Because the moisture content of the grain used by Harrison and Vas (4) was low, a project was initiated using the cultivar Park at five levels of moisture content from 12 to 20% (WB)b. The other factors in the experiment were three levels of cylinder speed (700, 900, and 1,100 rpm) with a cylinder diameter of 21 inches (533 mm) and three levels of total feed rate (100, 150, and 200 lb/min (45, 68 and 91 kg/min)). The concave clearance was fixed on the recommendations of Vas (3).
Keywords: effects of moisture content of wheat on threshing
Citation: Harrison, H.P. 1975. EFFECTS OF MOISTURE CONTENT OF WHEAT ON THRESHING. Canadian Agricultural Engineering 17(1):55-58.
Volume: 17
Issue: 1
Start page number: 55
End page number: 58
Date: 1975
Coverage: Canada
Located in: Volume 17 (1975)