8 io 
Journal of Agricultural Research 
Vol, XXIII, No. to 
results are representative of others obtained by using different kinds of 
ears; some of which were infected before planting. 
These soils, with the exception of the control, were soils in which abun¬ 
dant rootrots prevailed during the season of 1919 under field conditions 
in these representative counties. The stalks were cut longitudinally 
and then tested for iron compounds. At the same time the length of 
the stem from the growing point to the base was measured. This serves 
as the best index for showing relative amounts of stalk growth. The 
soil influence upon the distribution of iron is very marked in the different 
stalks, as is seen in Table I. 
Tabi.3 I. —Distribution of iron in vascular plate tissues in the nodes of three stalks grown 
from seed from the same seed ear in each of four different soils, under otherwise similar 
conditions for growth, at La Fayette , Ind., igig 
Source of soil. 
Height 
of 
plant. 
Distance 
from 
growing 
point to 
base. 
Color of leaves. 
Relative distribution of iron in 
vascular plate tissues. 1 
Cm. 
Cm. 
Garden 
150 
150 
120 
80 
Shelby County.... 
Bartholom e w 
County. 
Sullivan County.... 
90 
75 
100 
90 
95 
80 
80 
30 
40 
25 
12 
16 
16 
15 
20 
22 
20 
6 
4 
Normal green.... 
....do. 
_do. 
Slight yellowish 
green. 
Green.. 
Green. 
Yellowish green.. 
-do. 
_do. 
_do. 
Normal green.... 
-do. 
XXX- 
xxxxxx- 
xxxxxxxxx 
X-000 
XX- 0000 
X X X X-0000 
xxxxxxx- 
XXXX- O 
XXX - 000 
1 X=relatively large quantity of accumulated metals in nodes. 
—=trace, 
o no trace. 
There were cases, however, where the plants in some soils were appar¬ 
ently diseased and would not show the brownish purple discolorations 
of the nodal vascular plate. When tested for iron compounds no con¬ 
siderable quantities would be found in the nodal tissues. During 1920 
the microchemical method of detecting aluminum by use of logwood 8 
was applied, and it was then discovered that aluminum was present 
in these tissues in large quantities. After the usual test for iron, the 
aluminum test was made, and the results from the two tests usually 
suggested that aluminum may be equally as important or more so than 
the iron in its action upon the tissues. This test cleared up what ap¬ 
peared to be discrepancies in interpretation of the results in the field 
when nodal tissues would be found in stages of disintegration but without 
the usual amount of iron present in the tissues. The aluminum test 
would indicate the total quantities of both metals present in the tissues. 
INJECTION EXPERIMENTS 
Experiments were planned and carried out during the summer of 1920 
to determine the r 61 e of aluminum in the cornstalk, and whether or 
3 The logwood test consists in boiling the tissue to be tested for aluminum in a saturated solution of 
ammonium carbonate which has been colored deep red by logwood. This test should always be made 
after the relative quantity and distribution of iron in the tissue has been determined by the thiocyanate 
test, using a single piece of tissue for each test. 
