764 



Journal of Agricultural Research 



Vol. VI, No. 20 



field from 250 to 500 seeds were used in testing each lot, 500 being tested 

 in nearly every case. 



In all of the germination tests which were conducted in the germinating 

 chambers folded blue blotting paper free from soluble dye was used as 

 germinating beds for the seeds of the clovers, alfalfa, black locust, and 

 Chamaccrista nicitans, and folded canton flannel for the seeds of the other 

 kinds of plants. In the green house tests both sand and steam-sterilized 

 potting soil were used. 



VIABILITY OF IMPERMEABLE SEEDS 



In May and June, 191 4, 128 lots of seed from 1 to 5 years old were tested 

 for germination, and the viability of the seeds remaining impermeable 

 after six days was determined and compared with the viability of the 

 seeds which softened in the first six days of the test. 1 Table II sum- 

 marizes the results. 



Table II. — Viability of impermeable seeds from I to 5 years old 



Kind and age of seed. 



Red clover: 

 5 years. . . 

 4 years . . . 

 3 years. . . 



2 years . . . 



1 year. . . . 

 Alsike clover: 



3 years. . . 



2 years . . . 



1 year. . . . 

 White clover: 



3 years. . . 



2 years. . . 



1 year. . . . 

 Sweet clover: 



4 years . . . 



2 years. . . 

 1 year. . . . 



Alfalfa: 



3 years .... 



2 years. . . . 



1 year 



Hairy vetch: 



S years.... 



1 year 



Crimson clover: 

 Okra: 3 years. . 

 Chamaecrista nicitans: 



Number 

 of lots. 



2 years . 



4 years 



Robinia pseudacacia: 

 At least 5 years. 



Average percentage of — 



Germina- 

 tion. 



34 

 43 

 34 

 39 

 26 



J 5 

 7 

 6 



12 



i-5 

 4 

 10 



7i 

 69 

 67 



57 



59 



65 



9 



36 



25 



Imperme- 

 able seeds. 



59 

 43 

 58 

 60 

 74 



81 

 90 

 90 



82 

 90 

 87 



98 

 95 



2 5 



2 8 



26 



87 



43 

 54 



Viability 

 of imperme- 

 able seeds. 



99 

 96 



99 



99 



100 



100 

 100 

 100 



95 

 100 

 100 



100 



98 



100 



100 

 100 

 100 



100 



100 



100 



92 



85 

 95 



Viability of 

 seeds which 



softened 

 in six days. 



83 



75 

 81 

 98 

 99 



79 

 70 

 60 



44 

 80 

 92 



75 

 80 



91 



95 

 96 



99 



61 



7i 



88 



69 

 63 



54 



1 To determine the viability of the impermeable seeds, the seed coats of 20 seeds from each lot (or all 

 seeds remaining impermeable after six days if not more than 20) were cut with a knife, and these seeds with 

 cut see I coats were then subjected to germination conditions for seven days. 



