NoV. 1,1925 
Stimulating Germination of Western White-Pine Seed 891 
Table I. — Maximum germination according to each location and medium for 
stratification 
Stratification 
Secondary treatment 
Germina¬ 
tion « 
Location 
Medium 
Nature 
Period 
Olay loam bench.... 
Sandy.. 
Greenhouse.. .... 
Days 
9 
9 
9 
3 
9 
3 
6 
9 
3 
30 
Per cent 
&19.5 
19.5 
23.0 
39.0 
21.0 
32.0 
‘39.0 
14.5 
31.0 
32.0 
21.0 
32.0 
67.0 
Do__ 
.do_ 
Incubator_ 
Do__ 
Clay loam.. _ 
_do.... 
Do.... 
Sawdust _ _ _ 
_do _ __ 
Do__ 
Duff —. 
do _ _ . _. 
Loamy sand_ _ 
Sandy_ 
_do_____ 
Wet bottom land_ 
Clay loam_ 
Greenhouse__ 
Clay loam cellar_____ 
.....do_ 
Incubator......... 
Not stratified..... 
Check.. 
_do __ 
Do___ 
_do_ 
Greenhouse __ 
Do____ 
_do _ 
No heating _ .. _ 
Clay loam bench_ 
Clay loam. 
Tips cut with knife... 
Not stratified___ 
No heating; tips cut with knife_ 
° Seed bed covered with moss mulch, except as otherwise noted. 
* Seed bed uncovered. 
• Seed bed covered with tar paper. 
Though showing a slight increase in some cases over the check 
tests, this method of stratification failed to give satisfactory results. 
Thirty days’ simple treatment in the warm moist sand in the green¬ 
house or three days’ moist heating in the incubator gave almost as 
good returns as did any of the stratified samples. 
Germination by autumn sowing of the earliest as well as the 
later stratified seed, and also germination from the spring sowing 
of all of these the following year, were much below the percentages 
in Table I, even below the earlier check tests. Failure was shown 
by careful cutting tests to be due to rotting of the seed. 
Germination of seed placed in sawdust was slightly better in most 
cases than from the other media, and the later tests show that the 
seed may remain unimpaired longest in sawdust. Bark-free saw¬ 
dust was used in order to avoid the possibly injurious* effect of tannin. 
The tests bring out very clearly the beneficial effect of a moss 
mulch in aiding germination, for in more than 90 per cent of the 
cases the highest tests occurred in the mulched bed; and this method 
of preserving moisture of both air and soil and of equalizing the 
temperature promises better germination in seed beds in Montana 
and Idaho, where the atmospheric humidity is lower and the diurnal 
fluctuations in temperature are greater than in the Central or 
Eastern States. 
CHEMICAL TREATMENT 
The treatments designed to hasten germination through corrosion 
of the seed coat by chemicals included soaking for periods of 8, 15, 
25, 35, and 45 minutes in concentrated solutions .of sulphuric,'ace¬ 
tic, and citric acids. One of the samples was heated by the addi¬ 
tion of water to the sulphuric acid. Some were treated for 15, 30* 
60, 120, and 180 minutes in saturated potassium permanganate 
and potassium sulphate, and others for 5, 10, 20, 30, and 60 minutes 
in carbolic acid. Each of the samples chemically treated was washed 
in 12 waters to prevent further absorption and chemical injury to 
the seed kernel. , • 
74333—26f-7 
