Dec. is, 1925 Studies in Western Yellow Pine Nursery Practice 1113 
Counts of germination and survival were made about once a week 
after germination started during both seasons. At the end of the 
season a count of all living seedlings in the counting areas was made 
as a check on the total brought forward weekly. Also a final count 
of the total number of surviving plants outside the counting area 
was made to determine how closely the counted areas represented 
the rest of the plot. Survival counts of the transplants were made 
in the early summer and fall of 1915. 
When seedlings were taken up for transplanting in the fall, a 
sufficient number from each plot in each bed to give a good average 
were selected arbitrarily, ana measurements of length of main tap 
root and length of stem to tip of bud were taken. The plants were 
carefully dug to a depth of about 18 inches, and the soil was loosened 
from the roots with the fingers so as to bring out practically all of 
the main root system with the plant. In addition, the 1913 samples 
were washed and surface-dried and divided at the ground line, the 
two lots of roots and tops being weighed to centigrams. The 1914 
samples were not weighed, but were measured to obtain the average 
length of leaf in the main top and the diameter of the stem at the 
ground line. In the fall of 1914 measurements were taken sepa¬ 
rately according to month of germination. Measurement of the 
length of root was omitted for the stock taken from the 1914 beds 
in the spring of 1915. 
In the fall of 1915 each tenth transplant from each lot in the trans¬ 
plant bed was measured to determine the average height of stem 
and diameter at ground line. 
At the time seedling stock was measured about five plants typical 
of those with average measurements were selected from each lot 
and pressed. Photographs were made of typical seedlings from each 
of the three degrees of shading and also of seedlings from the unshaded 
bed, to show the relation between month of germination and size of 
the plants. 
DATA 
The evidence brought out by the experiments is, briefly, as follows: 
The unshaded bed in 1913 produced much the largest total germi¬ 
nation for the season, one-quarter shade being 20 per cent less, and 
one-half shade 50 per cent less. The same marked relation is shown 
by the 1914 beds, although the decrease in germination in the shaded 
beds is proportionally not so great. 
The rate of germination was most rapid in the unshaded beds in 
both years. In 1913 the ratio was 45 for no shade, 35 for one-quarter 
shade, and 20 for one-half shade. The relation in 1914 is shown 
graphically by the curves in Figure 3. The general form of the 
curves is the same, but the curve for the unshaded bed rises more 
rapidly than those for the shaded beds. 
Percentage of germinated seedlings surviving at the end of the 
season is greatest in the unshaded beds in both years, both for the 
individual months of germination and for the plots as a whole. 
Expressed in percentage of plants germinated, the proportion in 
the 1913 beds was 94.6 per cent for no shade, 78.4 per cent for one- 
quarter shade, and 85.9 per cent for one-half shade. In the 1914 
