ACCUMULATION OF ALUMINUM AND IRON COMPOUNDS 
IN CORN PLANTS AND ITS PROBABLE RELATION TO 
ROOTROTS 1 
By G. N. HoFFER, Pathologist and Agent, Office of Cereal Investigations, Bureau of 
Plant Industry, United States Department of Agriculture, and Associate Botaniste 
Purdue University Agricultural Experiment Station, and R. H. Carr, Agent, Offic, 
of Cereal Investigations, Bureau of Plant Industry, and Associate in Nutrition, Purdue 
University Agricultural Experiment Station 
INTRODUCTION 
The rots of the roots and stalk parts of the corn plant present a very 
complex problem, the entities of which are difficult to isolate for study 
and interpretation. Certain fungi and bacteria, which are more or less 
common in all fields in which com is grown commercially, are almost 
always present in these rotted tissues. At times the rot diseases may 
be very severe, but the damage caused by them seems to be influenced 
by certain soil conditions which are associated with deficiencies of the 
essential nutrients or with unbalanced combinations of available salts 
for absorption by the plants. Frequently the extent of damage may 
vary markedly in certain parts of fields or in different fields wherein the 
same seed stock had been planted. 
One of the most common characteristics of root rotted plants and of 
plants growing in certain areas in some fields is the brown to brownish 
purple discoloration of the vascular plate tissues of the nodes, as shown 
in Plates 2 and 5. This nodal discoloration has been observed in plants 
in all stages of development. It has been found in plants growing in 
all parts of the Com Belt. 
The most common difference between plants which show indications 
of being diseased and those which are of normal growth and bear normally 
matured ears is this almost universal brownish purple discolored con¬ 
dition of the nodal tissues. Attempts to isolate organisms from these 
tissues frequently prove futile, although in a large majority of cases the 
common Fusarium moniliforme Shel., Gibberella saubinetii (Mont.) Sacc., 
a white bacterium, Penicillium sp., Rhizopus sp., and others are found 
to be present, especially if the nodal tissues in the lower parts of the stalk 
are cultured. 
This nodal discoloration has been found in young plants which show 
no rot lesions whatever on the roots and from which no organisms could 
be isolated. Later in the season, however, abundant rootrots have 
developed in the plants, especially in “spots” in the fields where the 
majority of the plants showed these nodal discolorations, and much 
damage resulted. Field observations and experiments show that the 
largest numbers of seedling injuries also occur in the soils where these 
1 Accepted for publication July 23,1921. The results reported in this paper have been obtained in inves¬ 
tigations conducted jointly by the Office of Cereal Investigations, Bureau of Plant Industry, United States 
Department of Agriculture, and Purdue University Agricultural Experiment Station. 
Journal of Agricultural Research, 
Washington, D. C. 
abr 
(801) 
Vol. xxm, No. 10 
Mar. 10, 1923 
Key No. G-286 
