NURSERY PRACTICE ON THE NATIONAL FORESTS. 
19 
of the growing season at the nursery. When feasible the seed 
should be graded so as to eliminate the weak seed in the beginning 
and prevent the production of stock which is undesirable and will 
have to be discarded later on. Other things considered, the larger 
seeded forms of a species are to be preferred because they produce 
larger plants in the same length of time than the smaller seeded 
varieties. 
In no case should seed be used whose germination per cent is less 
than the average for the best fresh seed of the species. Germination 
tests should be made, and the seed which is found unsuitable rejected. 
The use of seed whose quality is not known may result in very thin 
stands of seedlings and thus upset nursery and planting plans for a 
year or two. When regular germination tests have not been con- 
ducted, some knowledge of the quality of the seed may be obtained by 
cutting open 200 or more and noting the condition of the kernel or 
meat. If the kernel is plump and full and of a good 'cream or white 
color the seed is probably good. This test is not wholly a reliable 
or satisfactory one, however, since it usually gives higher percent- 
ages of good seed than are obtained when regular germination-test 
methods are employed. 
Seed which will germinate at the rate indicated in the following 
fable will generally prove satisfactory for nursery purposes. The 
figures were obtained through actual tests of 200 seeds of each species, 
sown in small flats filled with sand or soil and exposed to a greenhouse 
winter and spring temperature of from 60° to 80° F. The figure 
given under 100 days is not necessarily the final germination per 
cent of the species ; but the percentage shown for each species listed 
is a very good one for a test covering that period of time. 
Results of germination tests. 
Germination per cent. 
Species. 
In 20 
days. 
In 30 
days. 
In 60 
days. 
In 100 
days. 
2 
33.5 
30 
54 
7 
10 
25 
25 
44 
70-86 
60-70 
24-30 
5-10 
2-2.5 
60-65 
76-90 
80 
71 
41-46. 5 
30-36 
70-74 
21 
3 
40 
61 
64 
Picea engelmanni =. 
70-85 
40-45 
21-33 
3- 4 
70-75 
47-59 
12-14 
Pinus lambertiana 
68 70 
42 45 
Pinus ponderosa: 
Black Hills 
Colorado 
Arizona 
1 
Idaho 
56-62.5 
36. 5-42. 5 
75. 5-80 
69.5 
California 
86 5 
Pseudotsuga taxifolia: 
Rocky Mountain form 
Idaho 
43.5 
10 
30-38 
61-69 
46 
Coast form 
63 
Sequoia washingtoniana 
Thuja plicata 
47 
