Report of Committee on Diseases of Citrus, 
By P. H. Rolfs. 
Wither Tip. 
This disease, which manifests itself in 
so many different ways on citrus fruits, 
continued to be exceedingly virulent dur¬ 
ing the past year. The total amount of 
damage done by this disease was, un¬ 
doubtedly, greater during the last season 
than any season heretofore. 
Work upon it has been prosecuted quite 
vigorously during the past year, and 
some new and interesting facts have been 
brought out. Considerable difficulty is 
encountered from time to time because 
this trouble is frequently complicated with 
other disturbances. Any condition of the 
orchard or of the fruit that low¬ 
ers the vitality renders it more sus¬ 
ceptible to attack 'from this fungus 
(Colletotrichum gloeosporoides), so that 
many trees and much fruit is found infect¬ 
ed. Though this disease must be con¬ 
sidered a secondary difficulty, in many 
cases, the primary difficulty would not 
have been sufficient to cause the destruc¬ 
tion of the plant or fruit. 
Late Rust. 
It is a well-known fact that the rust 
mite causes very considerable russeting of 
fruit. This may occur either during the 
early portion of the mid-season, or when 
the fruit has nearly matured. As a rule, 
when the fruit has passed mid-season 
there is very little danger of russeting. 
This year, however, many orchards have 
russeted severely after the fruit had reach¬ 
ed its full size, and in many cases after 
the fruit had begun to color. Vigorous 
spraying with the usual remedies for pre¬ 
venting russeting proved of no avail. 
This occurred on account of the presence 
of the wither tip fungus, which produced 
a form of russeting that in general ap¬ 
pearance resembles the rust mite russeting 
to a considerable extent, and in many 
cases is mistaken for it. 
This form of russeting can, however, be 
readily detected by rubbing the hand over 
the fruit. When it is due to the rust mite 
the fruit feels smooth, while when it is 
due to the wither tip fungus the surface 
will usually be rough, something like rub¬ 
bing the hand over sandpaper. Not in¬ 
frequently the two forms of-disease occur 
on the same fruit. 
Tear Stains. 
This peculiar form of russeting mani¬ 
fests itself by streaks running over the 
fruit from the side that hangs uppermost 
to the point which is nearest the ground. 
The cause of this peculiar form of rus¬ 
seting is that somewhere above the fruit a 
twig occurs which has been infested by the 
fungus, and which contains the hold-over 
spores. Whenever sufficient rain or dew 
occurs to cause a dripping from this 
disease infected twig onto the fruit, the 
disseminating spores are liberated from 
the twig and carried with the rain or dew 
over the epidermis of the fruit. Many of 
the spores are left along in different 
places and these produce sufficient irrita¬ 
tion to the epidermis to cause russeting 
