LIBRARY 
TATE PLANT BOARD 
October 1950 ET-291 
United States Department of Agriculture 
Agricultural Research Administration 
Bureau of Entomology and Plant Quarantine 
THRESHER AND SEPARATOR FOR RED CLOVER SEED SAMPLES 
By A. W. Woodrow, Division of Bee Culture, 
and B. A. App, Division of Cereal and Forage Insect Investigations-i-' 
The red clover head consists of about 100 florets, each of which 
must be cross-pollinated to produce one seed. Consequently, to evaluate 
correctly the activity of pollinating insects, it is essential to save all 
seeds, including poorly developed, lightweight ones, which are ordinarily 
lost in threshing. Imperfect seeds must be taken into account also in 
determining the insect damage to the clover and in appraising the effec- 
tiveness of insecticide treatments. Because of the small size of the seed 
it is difficult to thresh the clover without loss. Hand threshing is effec- 
tive, but it is a time-consuming, dusty, and otherwise unpleasant task. 
Therefore, small machines were developed for threshing and separating 
this seed. 
Seed Thresher^ 
The thresher, pictured in figure 1 and diagrammed in figure 2, 
consists of two functional parts, a cylinder (A) and a stationary apron 
or belt (B^) against which it revolves. The cylinder is made by mounting 
a section of 9 -inch, 24-gage, galvanized -iron furnace pipe 8 inches long 
on wooden disks turned out of 7/8 -inch lumber. It is covered with cor- 
rugated rubber (C) such as is commonly used for stair treads or hall 
runners. This material is about 1/8 inch thick with eight corrugations, 
1/16 inch deep, per inch. It is cemented to the cylinder with reclaimed- 
rubber resin-base cement, the corrugations extending lengthwise in a 
1/ In cooperation with the Ohio State University and the Ohio Agri- 
cultural Experiment Station, and with the Bureau of Plant Industry, 
Soils, and Agricultural Engineering. 
2/ The authors are indebted to R. D. Barden, Department of 
Agricultural Engineering, Ohio State University, for advice in planning 
the construction of this thresher. 
