48 BULLETIN 428, U. S. DEPARTMENT OF AGRICULTURE. 
Taste VII.—Alfalfa plants transplanted in 1909 to hills 24 by 36 inches at 
Brookings, S. Dak., showing yields of seed, 1910 to 1913, inclusive. 
Yield-of seed per plant (grams). 
Species. No. 
10 6| i911 | 1912 1913 “J Avera 
we ee eee a eee 
Modiorwe sativa .* 8) ook 25. | 20711 145 2.80 | 3.70 | 0.924) 1.333 2.188 
Medicago sativa X Medicago | ; 
alien che eee Ors 20571 248 2.92 4.61 1.506 7 2. 436 
pte tn fe 20714 418 2.72 3.90 1.108 . 641 2. 092 
BN ee Sie oe etek oad 20716 263 3. 46 6.80 2.231 1.353 | 3.461 
eT ers ee eee a ee 20717 261 $244) | eee 421 - 038 | . 633 
a ee Be cet 20718 243 .35 084 352 .181 | 241 
Do ere ieee ac tees 20719 234 .37 025 074 - 085 | -138 
(DES See cee 20720 G2 |e Pere Ste ee 209 . 258 | . 233 
LUT 3 oa ee ie ea 20721 159 . 205 | 126 ATT . 157 | 241 
Dh eee RMSE Cpe 213 . 216 082 375 - 122 | . 198 
[oD aei os BEER sae eee | 20725 225 sy ae Ie ee 613 . 044 . 782 
IT d soe eS Gece 20726 | 238 1.44 1.22 . 586 DAT Ic bee 
Ube cage a eee | 24452 | 708 | 1.28 . 135 | . 405 210 -507 
Se Se ee eee 24454 | 434 Be i tas ah .180 073 | 147 
TE sale Se a ee 24455 | 156 | 53 366 | 213 115 306 
Ree ee Ps | 24456 5G) 0g poke a Ae 205 169 187 
WG ee noe ee ee | 2807 177 | .142 | . 07: 100] >. 105 
JTL a re 28071 122 47 | - 29 17 147 | 27 
Average yield of seed: | 
eilicaro Sativa... c=.) ee ee ee ee ee ame ee aie Sree 2.188 
Medicago sativa X Medicago | 
Palate soo 3 saw coc ns es ee ee Se | Re ice ee 2. 663 
Modicago ialeata=. <2 Se a fa | ee ee ee 347 
A summary of Table VII shows clearly the relatively low yield 
of seed from Medicago falcata. Allowing amply for the variation 
in its different forms, there is none that approaches the ordinary 
forms of Medicago sativa in seed production. In view of the ex- 
treme uncertainty of the seed crop in the case of common alfalfa, 
there is reason to assume that the utilization of Medicago falcata 
as a cultivated crop will be seriously handicapped by the precarious 
nature of its seed production. 
In addition to scanty seed setting and the material loss from 
shattering. an appreciable percentage of the seed is “hard” and of 
doubtful value for sowing. As previously indicated in this paper, 
50 per cent of hard seed is commonly found in the various strains 
of Medicago falcata. While the germination of a portion of this 
seed can be hastened by treatment, no thoroughly practicable method 
has yet been developed either for scratching the seed coat or ren- 
dering it more permeable to water by the use of chemicals. There 
is also an appreciable percentage of shriveled and nonviable seed, 
so that the proportion of readily germinable seed rarely exceeds 40 
per cent. Preliminary tests indicate that the viability increases with 
age to a limited degree, aging apparently reducing the Pee 
of hard seed. 
The comparatively small size of the seed offsets to some extent for 
agronomic purposes the effect of the high percentage of hard seed. 
There are approximately 325,000 to 490,000 seeds of Medicago fal- 
