COTTONWOOD IN THE MISSISSIPPI VALLEY. gy 
There is an important relation between the height of the stump 
and the proportion of sprouts arising respectively from the root 
collar and the top of the stump.t. Of the two kinds of sprouts, only 
the former is of practical importance from ‘the standpoint of renew- 
ing a stand commercially. Sprouts from the top of the stump are 
dependent upon the stump for support, as they are unable at once 
to form an independent root system of their own. Cottonwood 
stumps, however, decay rapidly, and as the mechanical support of 
the new sprouts thus becomes weakened they are easily sloughed off 
and eventually are almost always thrown by the wind. The num- 
ber of vigorous sprouts from the root collar decreases with the height 
of the stump; other conditions being favorable, very low stumps 
(below 6 inches) invariably produce vigorous sprouts. Very little 
dependence can be placed upon stumps more than 15 inches high to 
sprout vigorously from the root collar. In fact, stumps higher than 
11 inches produce a disproportionately large number of sprouts from 
the top of the stump. If dependence is to be placed upon sprouts 
from the root collar, it would therefore seem advisable to cut the 
stumps as low as 6 inches, if possible, and certainly not higher than 
12 to 14 inches. Table 2 shows the relation between the height of 
stump and the kind and vigor of sprouts. 
TABLE 2.—Relation between height of stump and kind and vigor of sprouts. 
| | | 
Aver- | Aver- | Aver- | Aver- 
ges pase age | Aver- | ae |_age age | Aver- 
-| Height | Num- |number pmb nue age | Height} Num- number PUN Per nue age 
pien| pepobiy fort foo | height ||; of | berof | of |. 22 ..| °." 8b height 
stump. \stumps.|sprouts |SProU's) orou of _||stump. |stumps.| sprouts | SPT° CEOS Shire Obes | 
on root | 07 top | Sprouts sprouts on root | 0” ben Sereuts sprouts. | 
collar of on. collar. of oP. 3 | 
* |stump.|stump. * | stump. | stump. | 
| 
Inches. Feet. || Inches Feet. | 
+ 1 14 Oe ater 4 10. 00 | 23 9 0 42 31 0.08 | 
5 16 11 OF 1 6. 66 24 26 0 26 12 6.25 | 
6 7) ome ea Ve aes 1.20: | 25 16 0) 45 20 5.00 | 
7 ited ) 5 12 9.16 26 11 0 38 16 4.50 | 
8 12 7 | 14 20 9.33 | 27 14 0 38 18 4.75 | 
9 27 13 20 25 8.75 28 21 1 56 18 4.50 | 
10 31 eS 8 13 Cols 29 8 | 0 46 18 4.66 | 
11 20 8 2 10 8.25 | 30 36 0 6025) == 20 4.00 
12 16 9 30 39 6.66 | 31 29 | 0 51 22 4.16 
13 32 3 48 Bye a 7.00 32 Se oe 0 44 15 5.08 
eat: 51 rds 21 28 7.16 | 33 20)... 0 54 FA | EE 
15 42 6 17 23 7.66 34 27 0 63 14 3.66 
16 23 3 32 35 6.16 35 18 0 37 8 4.25 
Piel 57 2 36 32 7.08 | 36 25 O67 10 3-16 
18 37 0 42 35 (ele | 37 13 0 74 9 3. 66 
fe at® 7 0 62 20 6.00 | 38 9 Oe as 10 4.58 
20 41 1 4s 30 5.50 39 5 OR es a7 12 3.41 
21 23 0 24 18 6216 40 2, 0. 65 10 3.16 
22 10 0 37 22 5.25 41 ae Lt a ag 16 4.58 
| 
1** The Cottonwood (Populus deltoides) : A Tree Study,’’ Master’s Thesis, by Julius V, 
Hofmann, University of Minnesota, April, 1912. 
8471°—Bull. 24—13——3 
