Nov. 1,1925 
Stimulating Germination of Western White-Pine Seed 893 
may be used on a large scale for spring sowing at the nursery. It 
requires only a zinc-lined vat as acid container, running water, and 
paraffined hardware cloth baskets for dipping and rinsing the seed* 
After the treatment the acid is somewhat colored but has not lost its 
value for sterilizing purposes. Dry seed only must be used for the 
acid treatment, for experiments have shown that wet or soaked seed 
are injured by the acid. 
These tests, particularly those in which the seed coat was removed, 
show beyond doubt that delayed germination in the seed bed the 
first season after collection is due entirely to the obstruction of the 
seed coat itself and not to any inherent physiological character of 
s. 
60 
50 
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30 
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SULPHURIC ACID 
•TREATMENT 45 MIN. 
IS 
jt 
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5 100 
co 
90 
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£ 80 
^ 70 
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^ so 
40 
30 
20 
10 
0 10 20 3p 40 . 50 60 70 80 90 100 101 
DAYS 
TIPS 
CUT 
1 
WITH 
WIFE 
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10 20 30 40 50 60 70-60 90 100 110 120 130 140 ISO 160 170 
DAYS 
Fig. 1.—Nursery germination of western white pine 
the seed. After-ripening or the need for a period of rest may still be 
factors to contend with, but at any rate these do not hinder germi¬ 
nation during the spring and summer following seed production. 
MECHANICAL TREATMENTS 
On the strength of the excellent results obtained from the cutting 
or removal of the seed coat, experiments were undertaken to devise 
a churning apparatus coated with emery or carborundum- dust for 
the reduction of the seed coat. At this time, however, T. R. Truax 
had produced such a machine by which red clover germination was 
materially hastened. Accordingly, several samples of western white- 
pine seed were sent for treatment. 
