Kraebel: Choosing the Best Tree Seeds 



489 



represented by the parent trees made 

 possible so large a number of compari- 

 sons and factor combinations that eigh- 

 ty-three tables were compiled to express 

 graphically the numerous relationships. 

 The interplay of the factors involved 

 can be indicated by listing them in 

 juxtaposition : 



Age of the parent tree. 

 Size of the parent tree. 

 Health nf the parent tree. 

 Growing space of the parent tree. 

 Altitude of the parent tree. 

 Latitude of the parent tree 

 Soil quality of the site. 



It will be appreciated that not all the 

 first column factors will affect all the 

 points in the second column, and also 

 that such a feature as "size of seed" 

 might influence both "establishment" 

 and "size of seedling " in its own colirmn. 

 It is not possible, within the limits of 

 the present article, to discuss the de- 

 tailed conclusions, but some idea of their 

 trend can be given by a consideration of 

 their practical application. The tabular 

 comparisons were variously decisive, 

 but, on the whole, the results have 

 served to formulate a number of recom- 

 mendations for cone collection and for 

 the selection of seed trees. These re- 

 commendations are not regarded as final, 

 for it is almost certain that the future 

 development of the plantations will 

 change some of our present ideas. 

 European experience has shown that 

 such long-lived plants as forest trees 

 require some years to reveal their 

 hereditary traits. In Sweden, for exam- 

 ple, the failure of many plantations 

 from imported seed did not become evi- 

 dent until twelve or fifteen years after 

 planting. The following recommenda- 

 tions a'-e based upon two years' study 

 of seedlings in the nursery. It seems 

 inevitable, therefore, that the observa- 

 tion, through many years, of the same 

 seedlings in various field plantations 

 must result in some reversal of opinion 

 and in the disclosure of facts at present 

 imthought of. 



1. Gather cones in a locality as cold 

 as or colder than the planting site. The 

 colder the habitat of the parent, the 

 stronger is the tendency of the seedling 

 toward early maturing of growth. 



2. Collect from open-grown trees 

 where practicable, since such trees pro- 

 duce larger crops of cones, larger yields 



Seed: 



(a) Yield of cones per tree. 



(b) Size of cones. 



(c) Yield of seed per tree. 



(d) Size of seed. 



(e) Quality of seed, germination per cent. 



Seedling in nursery : 

 (c) Establishment. 



(b) Size of seedling. 



(c) Rate of growth. 



(d) Hardiness. 



of good seed per bushel of cones, and 

 larger two-year-old seedlings than do 

 forest-grown trees. 



3. Seek large cones where practicable. 

 Large cones have large seeds which offer 

 better chance of seedling establishment 

 and produce large first-year seedlings. 

 (This advantage of size is usually lost in 

 the second year.) 



4. Collect from young or middle- 

 aged, sm.all or large trees, as convenience 

 demands. Young trees produce large 

 seed and vigorous seedlings; such trees 

 are easy to climb and permit rapid work 

 in collecting. 



5. Avoid trees growing on poor soil. 

 Such trees give low yield of good seed per 

 bushel of cones. Seedlings also seem to 

 inherit a stuntednsss of growth. 



6. Avoid extremely high altitudes in 

 collecting unless the ultimate planting 

 site is very high. High altitude trees 

 generally give small yield of good seed 

 per bushel of cones. 



7. Avoid trees diseased by fungous 

 growth, "conky" trees, for these give 

 low yield of good seed, and the seedlings 

 are inclined to be stunted. Until this 

 point is cleared by further study, it is 

 safest to assume that the tendency to 

 disease, or rather the lack of resistance 

 to disease, is hereditary. 



8. Avoid insect-infested cones because 

 of small amDunt of goad seed. Injects 

 work rapidly and the damage is worse if 

 the cone crop is light for the locality^ 



