FOREST TREE SEED AND SEED COLLECTING 



133 



valuable than indicated by standard germination tests and the higher 

 the quality of the seed the nearer the tree per cent corresponds with 

 the results obtained by germination tests. 



The reason why tree per cent lags so far behind germinative 

 capacity on all qualities of site is chiefly due to the fact that the 

 various causes which destroy the viability of some of the seeds 

 before ripening or between the period of ripening and seeding 

 also decrease the vitality of the others in varying degrees. When 

 the vitality is greatly impaired the seed may germinate but the 

 germ is usually weak, normal roots do not develop, and it soon 

 dies. Many years of observation of Scotch pine germination in 

 Europe show that the higher the germination not only the smaller 

 the number of dead kernels but also the greater the vitality of those 

 capable of germination. 



Bates 1 from tests on the seed of four species gives the following 

 average germinative energy and the energy period as compared with 

 the average tree per cent from spring field sowing and summer 

 field sowing. The table also shows the germinative energy after 

 the field tests. The field germination was under the most favor- 

 able conditions. 



1 Bates, C. G.: The technique of seed testing. (Proc. Soc. Am. For., 

 vol. VIII, p. 135. 1913.) 



