^.So Journal of Agricultural Research voi. xxii, no. 9 



Experiments conducted by the German Chief Forester Haack ^ at the 

 Eberswald Forest Academy from 1906 to 1909 confirm some of the results 

 of Dr. Cieslar and give additional information on the subject of seed 

 storage. His experiments were confined to seed of Scotch pine. He 

 found that exclusion of air can not wholly prevent a loss of germinating 

 power with increasing age of the seed. This is manifested less by a final 

 decrease of germinating percentage than by a falling off in germinating 

 energy. But compared with that of seed stored in the air, this decrease 

 of germinating power is extremely slight. After three years the air- 

 tight seed had a germinating power of nearly 90 per cent as against 22 

 to 70 per cent for seed stored in the open air in the same room. 



Another conclusion of Haack's was that in no case should seed that 

 has been shut up in air-tight containers without previous thorough 

 drying be placed in a storeroom in which the temperature is likely to 

 increase, even if only occasionally (for instance, in attics). This con- 

 clusion was based on two experiments. In one, two air-tight bottles 

 were placed on thermostats heated to 36° C. and left for eight weeks. 

 One of the bottles contained air-dried seed, the other seed from which 

 5 per cent of its weight in moisture had been removed in an exsiccator. 

 In the test, the former germinated only a little over i per cent, the latter 

 96 per cent. In a similar experiment at a temperature of 30° C, the 

 germination test at the end of four months gave 40 per cent and 9^ 

 per cent, respectively. It might have been just as well for Chief Forester 

 Haack to emphasize the necessity of thorough but not excessive drying 

 of the seed before placing them in air-tight containers rather than stress 

 the point of storing in a fairly cool room not subject to a rise in tem- 

 perature. Such rooms are to be had only by some special arrangement. 

 Later in the same article, Haack does state that in storing pine seed 

 air-tight, care should be taken that the seed is neither moist nor over- 

 dr)^ He decided that the degree of dryness which the seed has when 

 it comes from the kiln or when spread out in a well-heated room or 

 dried in the sun would probably be best — about i to 2 per cent lighter 

 than its average weight in the ordinary seed bin. His experiments 

 showed that long-continued drying is harmful to pine seed. The ger- 

 minating power of Scotch pine seed left in the exsiccator for four years 

 fell to 16 per cent at the end of that time, while the same seed not dried 

 in this way still show-ed a germination of 80 per cent. 



Haack conducted one experiment to determine the eft'ect of different 

 temperatures of the storeroom upon seed in air-tight containers. Scotch 

 pine was stored for three years in a room heated to a temperature oi 

 20° to 25° C, in an unheated room, and in a cellar i meter in depth 

 Both cellar and unheated room were free from frost in winter; in sum- 

 mer the unheated room was somewhat warmer than the cellar. The 

 results indicated that a temperature of 20° to 25° C. in the heated room 

 was injurious to the seed. The germination percentage dropped from 

 96 to 82 in the three years. With strong seed there was very little 

 decrease in germination of seed stored either in the basement or in the 

 unheated room. With weak seed, however, not thoroughly dried before 

 being placed in the container, there was, after three years, a difference 

 in germination of 20 per cent in favor of the seed stored in the basement. 



These experiments of Dr. Cieslar and Chief Forester Haack, while 

 thorough in themselves, w^ere confined to only four species, three of 



1 Haack [Otto H. A.], der kiefersamen. vErhaltnis zwischen keimprozent und praktischem 

 WERT, mehrjahrige /ufbewahrung ohne verminderung des keimprozents. In Ztschr. Forst. u. 

 Jagdw., Jahrg. 41, Hett 6, p. 353-381, i fig. 1909. 



