4 BULLETIN 475, U. S. DEPARTMENT OF AGEICULTUEE. 



termine what constitutes a good crop for different species have given 

 the following figures i 1 



Table 1. — Amount of seed per acre produced by different species. 



Species. 



Trees 

 per acre. 1 



Cones 



per tree. 



Seeds per 

 bushel 

 cones. 





Bushels. 



Pounds. 



10 



3.50 



1.00 







4.00 



1.50 



40 



.50 



.40 



7 



1.00 



1.00 







.SO 



1.00 



12 



1.25 



.80 



8 



7.00 



1.60 



Seed 

 per acre. 



Douglas fir 



Western yellow pine . 



Lodgepole pine 



White pine 



Red pine 



Engelmann spruce . . . 

 Sugar pine 



Pounds. 



35.00 



30.00 



8.00 



7.00 



4.00 



12.00 



= 89.60 



i Bearing seed in appreciable quantities. 



2 The sugar pine seed is large, so that this weight does not indicate a greater number of seed per acre 

 than is produced by some of the other species. 



GATHERING THE SEED. 



Before beginning the actual work of collecting the seed of any 

 species, information regarding the seed crop in various portions of 

 the tree's range must be obtained. Knowledge of the relative abun- 

 dance of cones and the possibility of economically collecting seed 

 in the different localities makes it possible to concentrate the work 

 where the best results 7 can be had at the least expense. Small, scat- 

 tered operations are the most costly. 



Cones of most of the pines take two years to mature. Those of 

 some of the junipers and c} r presses also take two years, and a few 

 require three years. It is often possible, therefore, to predict a crop 

 of any of these species in advance. Other conifers ripen their cones 

 in one season. 



Careful examination of both the cones and the seed is necessary 

 to determine when collecting should begin, because cones ripen at 

 different times in different parts of a tree's range and at different 

 altitudes and localities in the same region. The external appearance 

 of the cone is not a sufficient indication of the condition of the seed ; 

 a number of cones should be cut open and the seed themselves exam- 

 ined. So long as the seed are soft and milky they are immature. 

 When the squirrels begin to cut off cones for storing, collecting should 

 begin at once. Hard frosts, followed by warm days, hasten the 

 ripening and opening of cones, and for most species the period of 

 collection is short if the cones are taken directly from the trees. 

 Therefore, when once collection is begun it should be pushed forward 

 with all possible haste. 



Cones are collected from felled trees, from standing trees, and 

 from squirrel hoards. Where logging is going on it is often pos- 



1 U. S. Department of Agriculture, Forest Service Bulletin No. 98. 



