16 
BULLETIN 1087, U. S. DEPARTMENT OF AGRICULTURE. 
Division of the taproot occurs less frequently than in the Grimm and 
Turkestan varieties. 
Table 6 tends to show that branch roots in the southern-grown 
common alfalfa are perceptibly less abundant than in the Turkestan 
and Grimm. They are, however, relatively large, thus making the 
branching system appear somewhat more prominent (Table 7, col- 
umn 3) than the number recorded would indicate. 
Fig. 11. — Root systems of plants of Poona alfalfa (Medicago sativa), the growth of 
one season. 
Table 6. — Number of branch roots occurring in different kinds of alfalfa at 
Rcdfield, 8. Duk., in 1917, 1919, and 1920. 
[Studies in 1917 and 1919 made on 1916 seedings; in 1920, on 1915 seedings.] 
Plants 
observed. 
Counts of branch roots 2 mm. or more in diameter from crown 
to IS inches below. 
Kind. 
Num- 
ber, 
each 
date. 
Average 
distance 
apart 
(inches). 
May, 1917; 
1 season's 
growth. 
August, 1919; 
4 seasons' 
growth. 
October, 1919; September, 1920; 
1 seasons' 6 seasons' 
growth. growth. 
Mor- 
tality, 
1916-17 
(per 
cent). 
Aver- 
age 
branch 
roots 
per 
plant. 
Mor- 
tality, 
1916-19 
(per 
cent). 
Aver- 
age 
branch 
roots 
per 
plant. 
Mor- 
tality, 
1916-19 
(per 
cent). 
Aver- 
age 
branch 
roots 
per 
plant. 
Mor- 
tality, 
1916-19 
(per 
cent). 
Aver- 
age 
branch 
roots 
per 
plant. 
Southern-grown 
100 
25 
75 
32 
32 
1.37 
1.32 
1.45 
2.12 
1.56 
6.31 
2.18 
None. 
None. 
None. 
2.15 
3.88 
4.33 
13 
None. 
5 
3.52 
5.20 
4.34 
32 
9 
4 
3.68 
4.24 
3.96 
Turkestan 
Southern-grown 
common 
40 
1 5 78 
5 
None. 
None. 
5.93 
Decumbent yellow 
19 
22 
> 
11.47 
Prostrate yellow 
6.90 
1 The large number of branch roots in southern-grown common alfalfa is probably due to extensive plant 
mortality between 1915 and 1920, which probably left the plants with the greater branch-root development. 
