RESULTS OF A STUDY OF DOUGLAS-FIR SEED 



1001 



(5) After cones are partially opened, are the seed which cannot he 

 shaken out of especially inferior quality, or is it worth while to 

 obtain them by further drying? 



Three lots of cones (each from a separate tree) were found to be 

 only partly opened after a rather prolonged air drying (in the green- 

 house at the Wind River Experiment Station). x\fter all seed which 

 could be extracted were obtained, the question of the advisability of 

 still further drying came up. To decide this an additional three to 

 four weeks' drying was given, with the following results : 



State of cones. 



Weight of 



cleaned seed 



obtained, grams. 



Weight of 200 

 seed, grams. 



Germination, 

 per cent 

 of seed. 



Partly open. 

 Fully open . . 



70.414 

 7-913 



2.38s 

 2.333 



It will be noted that the seed last obtained were just as satisfactory 

 as those secured from partially opened cones, but that a relatively small 

 amount was secured. If the extra drying can be done at slight expense, 

 it would doubtless pay to do it. 



(6) Are only the seed which readily shake out of high value, or are 

 the ones left worth securing by further shaking f 



The shaking tests were made with a six-sided wire-screen box about 

 2 feet by 3 feet in size, which was rotated by hand by means of a 

 crank. This differed from the ordinary cylinder screen only in shape, 

 being square instead of round in cross-section. 



Twenty-five cones from one tree were used in the first test. It was 

 found that altogether these cones had 1,023 apparently good seed, an 

 average of 41 per cone. Five revolutions of the screen, or one-quarter 

 minute of shaking, secured 66 per cent of these. An additional two 

 minutes, or about 40 more revolutions, brought 1 1 per cent more. Still 

 another shaking, 60 revolutions in three minutes, gave 6 per cent addi- 

 tional, making a total of 83 per cent of the seed obtained. The re- 

 mainder could be secured only by cutting the cones to pieces. The 

 germination per cent for the seed obtained by shaking was respectively 

 41, 47 >^, and 33>^ per cent. It seems that the seed last obtained was 

 sufficiently valuable to make it worth securing, though the quantity of 

 it was not large. 



Tests 2 and 3 were somewhat similar to the one just described, ex- 

 cept that the amount of debris at each turning and the weight of the 



