Nov. 1,1925 
Stimulating Germination of Western White-Pine Seed 897 
Table IV. — Preliminary treatment in moist sawdust 
Manner and length 
of treatment 
Germination in 
each period 
Water 
Moist 
sawdust 
50 dsfrs 
100 days 
Hours 
24 
24 
24 
Untreated. 
1 
. Days 
13 
23 
32 
Per cent 
5.2 
17.0 
8.0 
2.8 
Per cent 
31.0 
53.5 
47.0 
29.5 
then be recommended both for greenhouse sowing in sand and vari¬ 
ous germinators arid for spring sowing in the nursery. It is neces¬ 
sary to maintain uniform medium moisture conditions by keeping 
the seed covered to avoid extremes of temperature, and by daily 
stirring to prevent development of mold spores. The soil tempera¬ 
ture in these tests fluctuated between 60° and 90° F. 
AFTER-RIPENING AND PERIOD OF REST 
The investigations hdve revealed several methods by which white- 
pine germination may be hastened, but the question still remains 
unanswered whether the seed requires a period for after-ripening or 
for rest before active germination can take place. In order to throw 
light on this problem fresh seed was collected from a squirrel cache 
in a 250-year-old pine stand September 4, immediately extracted, 
and sowed soon afterwards, both in sand in the greenhouse and in 
the nursery. This seed had all the appearance of ripeness and was 
extracted at once without artificial heat. 
Greenhouse sowing took place November 20. The sowing was of 
duplicate samples of 500 untreated seed and of seed with the tips 
cut as in the previous nursery tests. Of these the sample with tne 
tips cut began to germinate December 7, or 17 days after sowing, 
and continued until complete with 74.6 per cent on April 20 following. 
The untreated sample began to germinate December 13 and was 
complete with 79.2 per cent July 10 following. Those untreated and 
sown in the nursery germinated very rapidly soon after warm weather 
developed, one lot reaching 79 per cent germination before June 19 
and the other 83 per cent. 
The prompt and complete germination of this seed in tbe green¬ 
house proved without doubt that after-ripening for this seed is of 
small moment. It did lead, however, to the belief that the seed 
was not entirely ripe. In order to prove this point further, seed 
was collected at successive intervals during the next good seed crop 
and tested. 
The seed for this experiment was collected at intervals of about 
two weeks, from a well-developed tree about 75 years old, was 
extracted under ordinary September and October temperatures in¬ 
doors without stove or other neat, and sowed in triplicate samples in 
sand in the greenhouse November 21. The results (given in Table 
V and fig, 2) are very interesting in showing a consistent and 
more rapid germination for the earlier lots, but in every case a higher 
final test for the seed of later collection. _ 
CEREAL INVESTIGATIONS, 
