CONTROL OF THE ROOT, STALK, AND EAR ROT
DISEASES OF CORN.'
JAMES Rt. Ii)LBERT,
Pathologist, Office of Cereal Invecstigations, and
GEORGE N. OFFER,
.Associate in Botany. Indiana Agricultural .Experimn nt Station, and P'athologist and
Agent, Office of Cereal Investigations.
CONTENTS.
Page.                                      Page.
Importance of corn ..........................  3  ('ontrol measures ............................  9
Losses caused by these diseases ..............  3  Field selection.........................  9
Distribution ...............................  4  ('Curing and storage......................  11
Causes of the rot diseases ....................  Subsequent sorting of the seed cars......  11
Description of the rot diseases ...............  6  Germinator selection ....................  13
Symptoms shown i n the seedling stage..  t;  Shelling and grading ....................  19
Symptoms in the young-plant stage.....  7  Breeding ................................  20
Symptoms in the silk-and-tassel stage....  S  Soil relations ............................  20
Symptoms shown in the ear stage........  8  Conclusions ......... ........ .....  24
IMPORTANCE OF CORN.
C   ORN     is the most important field crop in the United States.              Its
value is greater than the combined values of whlleat, oats, barley,
rye, rice, grain sorghums, and buckwheat.             Among the cereals it is a
"highly productive crop, yielding on the average about twice as much
grain, and, including the fodder, over three times as much food per
acre as either wheat or oats." On its production depends, to a large
extent, our enormous beef and pork industry.
The commercial varieties include dent corn, flint corn, sweet corn,
flour corn, and pop corn. While all of these different kinds of corn
have been found to be susceptible to rot diseases of the roots and
stalks, the statements in this bulletin apply chiefly to the (ldent
varieties grown in the corn belt.
LOSSES CAUSED BY THESE DISEASES.
The lot diseases of the roots, stalks, and ears of corn cause great
losses, are    widely    distributed, have      distinct characteristics, and
require special control measures.
I The investigations on which this bulletin is based were conducted in cooperation with the Department
of Botany, Indiana Agricultural Experiment Station, and Funk Brothers Seed Company, of Blooming-
ton, Ill. The destructiveness of these diseases and the necessity of preventing their spread through seed
corn was brought to the attention of the Department by Mr. Eugene D. Funk, who had initiated the
investigation in Illinois upon his own farms.