WEED IMPURITIES IN AGRICULTURAL SEEDS 4! 



manure. This is true so far as seeds which get into 

 manure not thoroughly composted are concerned. 



Mr. E. I. Oswald made a series of experiments to ascer- 

 tain the vitality of seeds when placed in manure under 

 different conditions. Three kinds of manure were used 

 horse manure, cow manure, and horse and cow manure 

 mixed in equal parts. The manure was placed in sepa- 

 rate piles, and seeds inclosed in gauze bags were placed 

 in the manure and allowed to remain for varying periods 

 of time, in some cases 60 days, in others six months. This 

 lot contained 52 different kinds of seeds. After the re- 

 quired length of time, the seeds were planted in the green- 

 house, and it was found that they had become thoroughly 

 rotted and their vitality destroyed. In order to cover the 

 conditions usually followed by dairymen and gardeners, 

 where the manure remains but a short time, another set 

 of experiments was started in the fall. The seeds re- 

 mained in the pile only one month and were then planted 

 as in the previous experiment. The results of the exper- 

 iments entirely confirmed the previous ones, except in 

 the cases of the seeds of ribgrass, horse nettle, common 

 plantain, large ragweed, bitter dock, and mallow, which 

 were still firm. 



Early in the summer of 1908 we placed 31 different 

 seeds of weeds and seeds of a few cultivated plants in 

 gauze bags and left them in horse manure for five weeks. 

 The seeds were placed in this manure on May 10 and 

 were removed June 19. The seeds were then germinated 

 in the greenhouse. Only a small percentage of the fol- 

 lowing weed seeds were capable of germination. 



We also conducted some experiments in feeding vari- 

 ous weed seeds to animals, among them sour dock, quack 

 grass, and sunflower; very little seed was capable of 

 germination after it had passed the digestive tract of the 

 animals. It is well-known, however, that hard-coated 

 seeds do pass the digestive tract uninjured. Numerous 



