310 



Bulletin 312 



Two lots of seed were purchased on the open market from seed dealers. 

 These lots were grown in 19 10 and the tests on them were made in Decem- 

 ber, 19 10. The lot marked "11" retailed at $11 a bushel, and the lot 

 marked "12" at $12 a bushel. Samples of 100 seeds each were counted 

 out from these two lots, which samples were soaked in water or in acid 

 for varying lengths of time, as shown in Tables 6 and 7. (In no case 

 does temperature enter as a factor in the treatment accorded seed. All 

 were treated with water and with acid at about the same temperature, 

 which was near 70° F. Acid-treated seeds and their checks were handled 

 at the same time and placed in the germinator together, except as noted.) 



It is seen in Tables 6 and 7 that the seed experimented with is not 

 noticeably injured by treatment with concentrated sulfuric acid (sp. gr. 

 1.83) for lengths of time up to 120 minutes. When the seed is left in 

 longer, however, injury results to the seed coats and to the radicles of 

 many seeds. This is especially true for seed left in the acid for 230 to 240 

 minutes. The maximum germination was secured in Lot 12 after acid 

 treatment for 10 minutes, but the maximum was only i per cent higher 

 than for 30, 40, or 80 minutes treatment, and 2 per cent higher than for 

 the 120 minutes treatment. The maximum germination in Lot 11 was 

 secured from the samples treated with acid 100 minutes, but this per- 

 centage is but little larger than for lots treated with acid for a shorter time. 



It is seen that these tests were made with lots of seed that germinated 

 well when no acid treatment was given. The acid-treated seed, however, 

 germinated, on the average, better than the untreated seed, as is shown 

 in Table 8; in Lot 11 the difference in favor of the treated being 6.6 per 

 cent, and in Lot 12, 3.4 per cent: 



TABLE 8. Red Clover Seed 



(Summary of Tables 6 and 7) 



The lots of seed Nos. 1 1 and 1 2 had been handled in a commercial way, 

 which is necessarily somewhat different from the method used for seed 

 that is kept in the laboratory for experimental purposes. 



Effect of laboratory storage 

 Samples of these lots were stored in envelopes in a drawer of a laboratory 

 desk for four months, or from December, 1 9 1 o , to April ,1911. These samples 

 were then treated as shown in Table 9, and a germination test was made: 



