498 
Journal of Agricultural Research 
Vol. XXIII, No. 7 
pink color. What appears to be the same fungus is on com that is germinating badly 
in the field. 
Arzberger (4) investigated the cob rot of corn caused by Coniosporium 
gecevi Bub&k. It is reported that— 
Coniosporium has an economic significance in that it destroys the cob tissue as a 
saprophyte; its effect on the kernels is rather limited when compared with the injury 
of Diplodia , Fusarium , and other fungi. 
Pammel (24) briefly described a serious root rot and stalk disease of 
com and later with King (25) published their studies on a Fusarium 
disease of com and sorghum. 
This fusarium disease attacks the roots, the stalks, and the ears of com at least 
some seasons. It has not been determined whether all the symptoms are caused by 
the same organism or not. 
Under the subject heading “ Ear Rot/' it is stated that— 
the molds are of three kinds. One attacks the kernels, husks, cobs, and sheaths, the 
threads of the mold occurring thru the cobs and sheaths, and destroying the kernels 
completely. The second kind of mold produces a deep pink or red color. The threads 
of this fungus are felty and penetrate the husks. The kernel becomes brittle and red. 
The third type of mold attacks an occasional kernel and is not so serious. Its threads 
are white. A fourth fungus,parasitic in character, was found on the ears, stems, and 
sheaths, and also on the roots. It is known as Diplodia Rot. 
Regarding the Fusarium— 
the mycelium penetrates not only the living cells, but also occurs in the intercellular 
spaces. It occurs abundantly in the embryo and endosperm of the seed. The inocu¬ 
lation experiments indicate that the fungus enters not only with the seed, by seminal 
infection, but that the undeveloped shoots in the axils of the leaves probably are 
responsible for some of the infection in the field. The disease probably spreads 
largely with the seed com. 
No determination, of the Fusarium was made by the authors. They 
observed the perithecia of Gibberella abundantly on the sheaths and stem 
of corn plants but were unable to show that this fungus is connected 
with the Fusarium studied. 
•Hoffer and Holbert (18) in 1918 first published on their extensive 
studies of the root, stalk, and ear rot diseases of com. It was stated 
that— 
inconspicuous rotting of the stalks, of the ears, and of the roots, may take place with no 
apparent injury. The kernels from ears borne on diseased plants will have seedling 
characteristics which can be noted usually on the germinator. Those seedlings which 
have rotted embryos and stalks indicate the ears to be discarded for seed purposes. 
The harmful organisms referred to in this bulletin are species of Gibberella, Fusarium , 
Verticillium, Rhizopus, and Pseudomonas. 
No determination of the species was mentioned at this time. In a later 
publication (20) it is reported that— 
these rot diseases are caused by a number of factors working more or less together, 
some of which are well known and others less fully known. Investigations have 
shown that certain fungi G. acervalis (Moug) Wr. and G. saubinetii (Mont.) Sacc. as 
well as certain bacteria are commonly present in diseased com plants in the field. 
On the germinator those organisms as well as certain molds ( Rhizopus , Aspergillus , 
etc.) also may occur on diseased, weak, or immature kernels and seedlings. 
These authors in a recent abstract (21) on com root and stalk rots con¬ 
sider the pathogenes are chiefly species of Fusarium and Gibberella . 
The common wheat scab organism, G. saubinetii (Mont.) Sacc. is probably the most 
common pathogene responsible for much of the root and stalk rotting of com plants 
in the Central States. 
