18 VITALITY OF BURIED SEEDS. 



preservation of vitality at that depth as a result of the more dormant 

 condition of the seeds. (See PI. Ill and the diagram below.) 



As was anticipated, most of the seeds which were stored in the Seed 

 Laboratory preserved their vitality much better than those that were 

 buried. But there are a number of cases in which the seeds were 

 preserved practical!}' as well in the soil as in the laboratory, the deteri- 

 oration being ver}" small in either case. However, with but few 

 exceptions, an ample number of seeds remained germinable at the ter- 

 mination of the tirst year to produce plants in sufficient number to keep 

 the up-to-date farmer busy for a good share of the summer in sup- 

 pressing them. The average percentages of germination of all samples, 

 including the original test and both controls, are best shown in the 

 following diagram: 



Average germination of controls and buried seeds. 

 Original tests, 60. 2 per cent. 



Controls (chamber), 57.5 percent. 



(Amtrrds ( <rrfenliuuse ), 5.">.2 ]ier ivnt. 



Buried 6-8 inches, 20.5 per cent. 



Buried 18-22 inches, 2t).5 per cent. 

 Buried 36-42 inches, 31 per cent. 



HARD SEEDS. 



An interesting point in these first results is in the behavior of the 

 Trifoliums and closely related genera, including Lespedeza and Medi- 

 cago. Generally speaking, these seeds are considered to be able to 

 withstand very critical treatment, but the results of the first 3^ear-s 

 experiments show that the seeds of all of these deteriorated very greatl}^ 

 while in the soil. 



The white clover. No. 41, germinated only 1 per cent, and showed 

 one fresh sprout when taken up from the 18 to 22 inch depth and 

 nothing from the shallower or deeper trenches. The red clover did 

 but little better; No. li), a sample of the harvest of 1902, germinated 

 2, 4, and 1 per cent for the three different depths of 6 to 8, 18 to 22, 

 and 36 to 12 inches, respectively. Another sample of red clover. No. 

 51, germinated 4.5, 5, and 6 per cent, respectively, for the three 

 different depths. A third sample of red clover, No. 68, germinated 

 10.5, 15.5, and 14.5 per cent, respectively, from the three depths. The 

 last two samples were of Oregon-grown seed of the harvest of 1900. 

 The original sample of this seed. No. 54, contained 51.5 per cent of 



I 



