Decomposition of Sweet Clover as a Green Manure 129 



had been found to be due to poor germination, it seemed desirable to 



run germination tests on the seed used, and also to try the sulfuric-acid 



treatment. This method of treating seed to increase the percentage of 



germination is described by Love and Leighty (19 12). It consists 



essentially in allowing the seed to stand in contact with concentrated 



sulfuric acid until the hard seed coat is softened or removed. In these 



experiments sufficient acid was added to make sure that all seed was 



coated with it, and the mixture was allowed to stand for twenty minutes. 



It was then dumped into a large volume of water in order to prevent 



the heat of dilution from injuring the seed. Washing by decantation 



caused the removal of most of the loosened hulls. Finally the seed was 



washed on a cheesecloth filter until it was free from acid, and allowed to 



dry. The treated and the untreated seeds were then tested by germinating 



between filter paper. One hundred seeds were used for each trial. The 



results were as follows: 



Percentage of 

 Untreated germination 



seed after four 



days 



Lot I • 28 



Lot 2 30 



Lot 3 32 



Treated 

 seed 



Lot I 97 



Lot 2 98 



Lot 3 97 



Lot 4 95 



It is seen that the percentage of germination was more than trebled 

 by the acid treatment, and that practically complete germination was 

 obtained. Thirty per cent is probably a fair average of the results obtained 

 by other investigators in germination tests on untreated seed. A treat- 

 ment by which the quantity of seed required may be reduced by from 

 one-half to two-thirds, should be worth while. The procedure requires 

 little time, and the method is inexpensive since commercial acid may 

 be used. 



There may be some question whether the average farmer would be 

 successful in treating seed by this method. In this connection it seemed 

 desirable to investigate the effect of age on seed given the acid treatment. 

 The following results were obtained ten months after the treatment 

 was used: 



16 241 



