GERMINATION OF SEED AS AFFECTED BY SULFURIC ACID TREATMENT 297 



left in concentrated sulfuric acid for 24 hours still contained 9 per cent 

 viable seed. 



Following the work of Rostrup came that of Todaro, 1 who, working 

 independently, found that concentrated sulfuric acid of a density of 1.84 

 acted upon hard seeds of many leguminous plants, rendering them capable 

 of prompt germination. Hard seeds of various leguminous species were 

 found to withstand immersion in concentrated sulfuric acid without any 

 injury to their viability, for about one hour at a temperature of 25 to 

 28 C., or a somewhat longer period at a lower temperature. In all the 

 experiments with leguminous seeds treated with concentrated sulfuric 

 acid, the germination of the hard seeds was effected and a more rapid 

 and more uniform sprouting was secured. Upon such seed as sulla, 

 bird's-foot clover, Melilolus, black medick, and others, it was shown that 

 concentrated sulfuric acid not only secured the greater total germination 

 but appreciably hastened it. Cuscuta seeds showed that they were not 

 only resistant to the action of sulfuric acid, but their germination was in 

 many cases favored by the treatment. The seeds of Plantago lanceolata, 

 verbena, Rumex, spurry, foxtail, and some other seeds that frequently 

 occur as impurities in red clover seed, were all destroyed by a brief immer- 

 sion in the sulfuric acid, without any detriment whatever to the red 

 clover seed. 



Todaro concluded that were the seeds left to dry after treatment they 

 would not show the effect of the immersion in acid. This conclusion, 

 however, is at variance with the results obtained by the authors of this 

 bulletin. 



Later Thornber 2 used sulfuric acid and found that in connection with 

 the germination experiments the seed of acacia, mesquite, honey locust, 

 locust, and Kentucky coffee trees were made to germinate readily when 

 immersed for a short time in concentrated sulfuric acid in which chromic 

 acid had been dissolved, and then neutralized in a dilute solution of 

 potassium hydrate. 



Schneider-Orelli 3 conducted experiments with a number of species of 

 Medicago and found that when the seed was cut or filed so that the seed 

 coat was punctured, a good germination was effected. Sulfuric acid 

 treatment also gave good germination. More than three fourths of the 

 treated seed germinated, while only 3 out of 20 of the check lot 

 sprouted. 



Sulfuric acid was tried by Bolley 4 on several samples containing hard 

 seed, and it was found that the germination was markedly increased. 



1 See " Literature," page 336, for reference. 

 Ibid. 



Ibid. 



Ibid. 



