496 
Journal of Agricultural Research 
Vol. XXIII, No. 7 
the form of a coarse powder; it attacks the end of the kernel first, gradually working 
its way toward the cob. 
Valleau ( 36 ) in liis studies of com rots in Kentucky as well as those 
from other States, considers that Fusarium moniliforme will probably 
prove to be the most common cause of root and stalk rots of corn. He 
finds that— 
a microscropical examination of the pink crowns or pink stripes on kernels reveals 
the presence of hyphae and occasionally spores in them, between the seed coats. 
The development of reddish or black discoloration in the seed coats of com during 
and after germination, is an indication of infection with F. moniliforme. 
No mention is made of the importance or determination of other fungi 
in connection with his studies. In a later article (37) on the control of 
com root rot, it is stated that— 
thus far no disease free seed has been obtained by the method of selection. The 
results obtained indicate that infection takes place before the early dough stage. It 
probably occurs through the silks and is a result of infection of the exposed silk mass 
with F. moniliforme. Attempts to control com rot by seed treatment have given 
negative results. 
Barrett (5) reported on the dry rot in com as caused by several species 
of fungi. One of the most destructive being Diplodia maydis Sacc. 
(D. zeae (Schw.) Lev.). A second form of dryrot which is not uncommon 
is due to a species of Fusarium, and a third form is due to a sterile fungus. 
Later in‘conjunction with Burriil {6) studies were reported on ear rots 
of com. Four types of ear rots were recognized as caused by D. maydis 
and three different fusariums, designated i„ 2, and 3. 
The most extensive work was on Diplodia zeae . They observed— 
the slender threads penetrate the young tissue of the grains, cob and husks, progress¬ 
ing from cell to cell and extracting from their contents whatever is of value for food. 
Diseased ears left in the field under natural conditions eventually develop numerous 
pycnidia in the grains, giving them a black appearance. 
The best results of inoculations were obtained when the com was still 
in the thick milk stage. 
80% of silk inoculated ears produced the disease, 71.7% of those inoculated at the 
base and 48% so treated in the shanks were successful, while but 22% of the sprayed 
ears showed any signs of infection. All later inoculations altho fairly successful 
produced smaller percents of the disease than others. 
There was no direct evidence obtained that the infected ears on inoculated 
stalks were a result of the inoculations made. 
Fusarium 1— 
produces a rather dense, felty mass of white mycelium which extends between the 
kernels to the cob, causing it to become more or less diseased. 
The mycelium is established all through the diseased grains, corroding 
the starch and destroying the germs. 
The diseased portion of ears infected with Fusarium 2 have a deep 
pink to red color due to the pigment produced in the hyphae of the 
fungus. 
The felty mass of mycelium permeates the inner husks and silk and holds them firmly 
to the ear. 
Fusarium 3 forms a rot less complete in its destructiveness of the ear 
than that of the other forms described. Many of the infected ears have 
only a few scattered disease grains. 
Under some conditions, however, most of the kernels may become diseased and 
the cob more or less infected .... The mycelium is white, very sparse, and is 
