NURSERY PRACTICE FUR PRA1RIE-PLALN6 PLANTING 



L5 



The macerator can be used either for the threshing of dry-fruited 

 species such as Kentucky coffeetree, honeylocust, and black locust 

 (fig. 6, A) or for macerating fleshy- and pulpy-fruited species such as 

 mulberry, chokecherry. Osageorange, redcedar, American plum, and 

 various others (fig. 6, B). Some species such as ash are threshed dry 

 in order to separate the clusters of seed. The size of the discharge 

 opening is controlled by a metal slide, with which the operator regu- 

 lates the rate at which the material passes through the machine. 



For a number of the pulpy-fruited species, notably Russian-olive 

 and redcedar. the machine can be used first to thresh the fruit from 

 the leaves and twigs by running the machine at a rather high speed 



F33470C F3421S 



Figure 6.- — A, Threshing Russian-olive seed in especially constructed macerator, 

 seed warehouse, Fremont, Nebr. B, Macerating Osageorange. 



with the discharge slide wide open (fig. 6, A) and then for separating 

 the seed from the pulp by closing down the discharge opening and 

 decreasing the speed. In extracting pulpy-fruited species, water is 

 added through the hose attachment and serves to wash the pulp and 

 seed through the discharge opening after proper maceration. 



The capacity of the macerator is governed by the length of the 

 cylinder. Macerators now in use have cylinder lengths of 12 and IS 

 inches. For an all-purpose machine, one with K-iuch teeth clearance 

 has proved satisfactory since it will handle the small as well as the 

 large seeds; but in order to clean seeds of all sizes to best advantage it 

 is desirable to have a second machine with %-inch clearance for the 

 smaller seeds. 6 



A good power unit for operating this machine is a 1-hp. electric 

 motor, although small gasoline engines are equally satisfactory. 



6 A macerator in use at the Southern Great Plains Field Station of the Bureau of I'lant Industry, at Wood- 

 ward, Okla., is equipped with an adjustahle macerating plate so regulated that different clearance width- 

 can easily be obtained for the various kinds of seed processed. 



