1128 
Journal of Agricultural Research 
Vol. XXVIII, No. 11 
It is very desirable to eliminate this hold-over germination for several reasons. 
The most obvious objection is that a very irregular stand of seedlings is pro¬ 
duced. The seed-bed stand is uneven-aged, uneven in size, and uneven in its 
resistance to injury. Such irregular stands require heavy culling at the end of 
the second season or must be kept through the third season with its additional 
costs for all cultural operations. Either course is undesirable and expensive. 
Together with hold-over germination we have to deal with a first-season ger¬ 
mination from spring sowings which extends its activity throughout the summer. 
This aggravates the difficulties just mentioned, particularly the poor resistance. 
Seedlings originating late in the season are young and tender, and so undergo 
heavy losses. Death from the damping-off fungi is confined to seedlings three 
weeks old or less. Young seedlings are scorched by the hot sun of July and 
August and die more easily from slight drying of the surface soil than do their 
companions which are a month or two older. This necessitates the heavy ex¬ 
pense of shading the seed-beds with lath frames. Then often 20 to 25 per cent 
of these weak, not yet lignified individuals are lost over winter. Frost heaves 
the ground in late fall or early spring when the soil is moist and exposed, and the 
weaker seedlings are heaved out. To avoid this trouble mulching the beds with 
straw or similar material is necessary, but this in turn results in the breaking of 
tender stems while applying and removing mulch. 
In the endeavor to obviate these difficulties many attempts have been made 
to hasten the germination of the western white pine seed, among which may be 
mentioned: Stratification, sowing fresh seed, soaking in hot or cold water or in 
acids of different concentrations, dry and moist freezing, sowing in hotbeds, 
sowing of pregerminated seed, and mechanical methods of cracking, piercing, 
abrading or removing the seed coat. Most of these, however, are dangerously 
artificial methods which, experience has shown, tend to lower germinative capa¬ 
city and at the same time do not uniformly accelerate germination. 3 
FALL- VERSUS SPRING-SOWING EXPERIMENTS 
Because the results of these trials of spring sowing were all quite unsatisfac¬ 
tory, the possibility of fall sowing was considered. If the hold-over germination 
could thus be avoided the disadvantage of exposing newly made seed-beds for a 
longer time to the ravages of bird and rodent enemies, and to frost heaving of 
seed would be compensated for or could be controlled by other means. In 
actual practice the losses due to these causes have been small. 
During the growing seasons from 1914 to 1916 at the Priest River Forest Ex¬ 
periment Station, observations concerning the best season to sow were taken 
from plots sown for other studies. In one instance, fall-sown plots had con- 
pleted 83 per cent of their total germination before the end of May, while less 
than 14 per cent of the germination in spring-sown plots was complete at that 
time. Again fall sowings were 17 per cent higher in survival, and produced 
larger stock in every respect. 
In the fall of 1913 and spring of 1914 at Savenac nursery six plots, each con¬ 
taining 2,000 counted seeds, were sown on different dates. Germination from 
fall-sown plots was complete about 15 days before that from spring-sown plots 
started. (See fig. 1.) 
Twelve plots sown on October 27 and November 4, 1915, and on May 5, 1916, 
were watched during 1916. Hold-over germinations were much more numerous 
from spring sowing. Subsequent work has constantly given similar results. (See 
fig. 2 and 3.) 
* A full discussion of this subject is given in a manuscript thesis presented in 1917 to the faculty of the 
Graduate School of Cornell University: Rogers, E. C. delayed germination among the five- 
NEEDLE PINES. 
