WEED IMPURITIES IN AGRICULTURAL SEEDS 



37 



species studied by him, the age of seeds varied from 

 125 to 135 years, and that a few of the old seeds 

 germinated, notably those belonging to the pulse, 

 water lily, and mallow families. In this connection the 

 study made by Ewart on the Longevity of Seeds is 

 of interest. Thus in some of the common Indian mallow 

 or butter-print, 6 per cent of seed germinated after the 

 lapse of 57 years, the common shoo-fly after 57 years, the 



seed of white sweet 

 clover showed germi- 

 nation after 77 years, 

 and 52 per cent after 

 44 years, chicory after 

 10 years. In this con- 

 nection the experi- 

 ments conducted by 



Fig. 32. Seeds of some grasses, i, Dr ; W - J- Beal are also 

 quack grass; 2, 3, orchard grass; 4, 5, of interest. 



A number of years 

 ago he made an inter- 

 esting experiment on the prolonged vitality of the seeds 

 of some common plants, testing for vitality at different 

 periods of 5, 10, 15, 20, and 25 years 1 . The seeds were 

 placed in sand in bottles slanting downward so that water 

 could not enter, and buried in the soil, 20 inches below 

 the surface. The seeds were all grown the year they were 

 buried. The * indicates that the seed germinated. 



The following table indicates the vitality at these 

 periods : 



5TH IOTH I5TH 20TH 25TH 



meadow fescue; 6, English rye grass. 

 (Hillman.) 



