16 MISC. PUBLICATION 4 3 4, U. S. DEPARTMENT OF AGRICULTURE 



The cylinder speed is controlled by the graduated V-pulleys permitting 

 speeds from approximately 400 to 1,700 r. p. m. It has been found 

 that optimum operating speed for greatest effectiveness varies con- 

 siderably for the different species. As reported by Carl Taylor, 

 capacities of the macerator are as follows: For a machine having a 

 cylinder 12 inches long with teeth spaced at %-inch clearance, the usual 

 run of chokecherry is 2,000 to 2,500 pounds of the fruit per day, 

 depending on the condition of the fruit. For redcedar, which is more 

 gummy, 1,000 to 1,500 pounds is a good day's run. The machine can 

 depulp from 2,000 to 3,000 pounds (dry-weight basis) of Russian-olive 

 seed which has been previously soaked, or 1,000 pounds of buffalo- 

 berries in a day. A similar machine with an 18-inch cylinder and 

 }£-inch clearance depulps 4,000 to 5,000 pounds of plums per day. 

 Pro-rating the plum cleaning over the entire crew, washing, fanning, 

 and other handling, the output is 950 pounds of fruit per man-day, 

 and the total cleaning cost 15 cents per bushel of fruit, or 2){ cents per 

 pound of clean, dry seed. The speed of threshing varies considerably 

 with the dryness of the material and the proportion of leaves and 

 brush. The 1935 Russian-olive crop threshed around 2 to 4 tons per 

 day. Honeylocust pods, if reasonably dry, thresh out fast enough so 

 that the yield of clean seed is 400 to 600 pounds per day, but if the 

 pods are well broken up by tramping before they are put through, an 

 output of 1,100 to 1,500 pounds of clean seed is possible. 



In addition to the macerator, other implements have been used with 

 good results in tree-seed extraction work, among which the more suc- 

 cessful are the old-fashioned restaurant potato peeler, food choppers, 

 concrete mixers, hammer mills, feed grinders, and grain threshers. 

 Usually it will be found that such implements work exceptionally well 

 for one or two species but cannot be made to perform successfully 

 over a wide range of species. 



Following the macerating process, further cleaning of the seed is 

 necessary. For dry-fruited species such as ash and locust, the wings, 

 hulls, and other debris are removed by running the seed through a 

 fanning mill. For a few species like Osageorange, washing the seeds 

 through screens to separate the heavy, larger pieces of pulp is helpful, 

 if done previous to floating off the pulp. In a number of other pulpy 

 species, washing through screens, followed by drying and fanning, 

 will complete the extraction. The tiny seeds of serviceberry are 

 more difficult to separate from the pulp and fully clean by any process. 



Where there is a considerable differential in weight, light seed can 

 be separated from well-filled seed of similar size by means of a fanning 

 mill. This will be most effective with seed having thick, bony 

 coverings. 



Seed of the fleshy-fruited species can usually be separated from the 

 remnants of the pulp and from light seed by notation. This method 

 is based on variation in buoyancy under agitation in water. Good 

 sound seed is ordinarily quite heavy and will quickly sink to the 

 bottom, whereas pulp and poor seed will either float or settle more 

 slowly after being put in suspension. A quantity of the macerated 

 material is placed in a slightly tilted large wash tub into which a 

 stream of water from a garden hose is directed at such an angle as to 

 create a rotary swirl and a lifting effect upon the material. Slight 

 stirring of the material in the bottom of the tub is_also necessary. 



