14 



For cleaning seed it is desirable to select a few capable men and keep 

 them at it steadily rather than to extract the seed with any available 

 help as fast as it is collected. More seed will be cleaned and a better 

 job accomplished as the men become trained in the work. Cleaning 

 immediately the fruits with soft, juicy pulp which spoil quickly, and 

 delaying the extraction of seeds which can remain for some time in 

 the fruit or pods without harm, will permit spreading this work 

 throughout the season without injury to the seed. It should be realized 

 that even the drier fruits cannot be left for long in a poorly ventilated 

 building without increasing the danger of loss through molding 

 and decay. 



Length of fermentation period of the fleshy fruits of mulberry, 

 buffaloberry, and chokecherry influences the amount and speed of 

 germination. In a series of tests by Carl Taylor of the Prairie States 

 Forestry Project it was found that seed from mulberry fruit, fermented 

 in water from 24 to 48 hours, showed a decidedly higher and more 

 rapid germination than that^unfermented. Further fermentation 

 beyond the 2-day period markedly decreased the amount and speed 

 of germination and 4 days of fermentation caused complete loss of 

 viability. The same trend occurred in buffaloberry although the 

 optimum fermentation period extended up to 4 days. The chokecherry 

 snowed some slight improvement in germination from fermentation 

 up to 4 days, although this length of fermentation in deep containers 

 pickled the pulp, rendering extraction more difficult. 



Although Taylor's tests indicate that a limited fermentation of 

 pulpy fruits before extraction is beneficial to germination, for safety 

 it seems advisable to hold fermentation during extraction to a mini- 

 mum. It probably should not be permitted at all if the seed is to be 

 held for a long period in dry storage. 



METHODS OF EXTRACTION 



An effective extractory should contain ample floor space, should be 

 provided with running water, floor drains, and electricity, and should 

 be insulated and heated to permit winter work. A cold-storage 

 chamber for stratifying and storing seed will also prove essential 

 where these processes are to be conducted on a large scale. 



Standard equipment at an extractory should include several dust- 

 proof electric motors — preferably %, }{, and 1 hp. — seed macerator, 

 seed scarifier, rotary drier, two large fans, fanning mill, tanks and 

 barrels, stratification boxes, and containers for storage of seed. Of 

 necessity there will also be considerable miscellaneous equipment. 



In this connection it should be mentioned that seed can be safely 

 extracted with very little equipment provided more labor is used in 

 the process. Large quantities of seed have been extracted with such 

 simple equipment as a few lengths of 4- to 6-mesh hardware cloth 

 through which the fruit is rubbed, and a few buckets or barrels to 

 serve as containers. A plentiful water supply for washing and floating 

 off pulp is, of course, essential. 



The macerator developed for seed extraction by the Forest Service, 

 when used in conjunction with a fanning mill, extracts rapidly and 

 cheaply the seed of most deciduous species, as well as juniper seed. 

 It is of all-metal construction and built on the principle of a threshing 

 machine with cylinder and concaves. 



