APPLE DISEASES 
Ripe Rot 
Sclerotinia fructigina 
See Brown Rot. 
Root Buiaur. See Blight under Pea 
ROSETTE 
Rosette has doubtless existed for ages, 
and has affected many kinds of forest 
trees, shrubs, plants, and fruit trees. 
This seems a reasonable inference, from 
the fact that the causes have existed for 
ages and the results would naturally fol- 
low. It is only in recent years, however, 
since fruit growing for commercial pur- 
poses has become general, and since it is 
being studied with scientific accuracy, that 
rosette has been observed, and become 
a subject of considerable controversy. 
When first observed, it was supposed to 
be confined to the arid regions, where 
the soil was largely a volcanic ash, or dis- 
integrated basalt, and where the sun was 
hot enough and the air dry enough to 
cause a rapid evaporation from the leaf. 
This theory is now abandoned by those 
who have carefully studied the subject, 
and it is known that the disease exists 
in the humid regions of many countries 
as well as in the arid regions, although 
it is conceded to be more prevalent in 
arid than in humid regions. It is known 
too, that the disease is not confined to 
one species of trees, or even to fruit 
trees, but that ash, willow, walnut, elm, 
oak, and many other varieties of trees 
are affected by it. In the arid regions 
of the Pacific coast states, the disease 
became so prevalent, where it was gen- 
erally known as “Apple Rosette,” that I 
determined, if possible, to find the cause 
and the cure. I therefore began investi- 
gations, first in my own orchard, extended 
my observations to other orchards in our 
community, later to other communities, 
and later still to other states. Soon after 
beginning my investigations, I wrote fifty 
letters to practical orchardists, fruit in- 
spectors, and professors in our state insti- 
tutions, to get, if possible, their many 
viewpoints, and to see if there were any 
general agreement, or clearly defined con- 
sensus of opinion on the subject. The 
answers to these letters were very in- 
477 
structive, but showed wide differences of 
opinion as to causes. 
My own observations were about as 
conflicting as the replies to my letters; 
for often when I had discovered what 
seemed to be the cause, I found rosette 
existing under conditions where the sup- 
posed cause was not apparent. However, 
I have kept up my investigations and 
with this disease in mind have visited 
many of the orchard sections in Wash- 
ington, Oregon, California, Idaho, Mon- 
tana, Utah, Colorado, and Texas. 
The Causes Assigned 
I have given here a list of the causes 
assigned for rosette, and in another place 
in this article have quoted more fully 
from the authors, using this as a mere 
catalogue selected from the replies, as 
follows: 
Too much water. 
Not enough water. 
Too much alkali. 
An unbalanced food ration. 
Too much barn yard manure. 
Clean cultivation. 
The puddling of the soil in irrigation. 
The bud moth, which injures the leaf 
buds, 
Cut worms which work on the leaves 
and buds. 
Some kind of bacterium or microbe. 
An enzymatic ferment, induced by in- 
jury to the bark of the roots. 
A rapid evaporation from the leaf. 
Lack of aeration of the soil. 
Hard pan, which retards root develop- 
ment. 
Scab soil, which lacks plant food. 
Lack of proper drainage. 
Cramping the roots in planting. 
An anemic condition of the tree simi- 
lar to anemia in the human organism. 
Some of the replies included more than 
one cause, giving evidence that the wri- 
ters had observed it under conditions that 
were dissimilar. 
Method of Investigation 
In my investigation, I applied two 
modes of reasoning. The first was in- 
ductive, in which, by the examination 
and study of a large number of cases, I 
