UNITED STATES DEPARTMENT OF AGRICULTURE 
f BULLETIN No. 924 f M 
Contribution from the Bureau of Plant Industry "^fiVV /«fi^" 
jWlVi. 
WM. A. TAYLOR, Chief 
&J? 'T>-ru 
Washington, D. C. 
PROFESSIONAL PAPER 
January 26, 1921 
TEAR-STAIN OF CITRUS FRUITS. 
By John R. Winston, 
Pathologist, Office of Fruit-Disease Investigations. 
CONTENTS. 
Page. 
Description of the disease. 
Renew of the literature. . 
Spraying experiments 
Cultural work 
Histological examination. 
1 Inoculation experiment.: 
2 | Conclusions. 
Summary 
Literature cited 
I'oge. 
DESCRIPTION OF THE DISEASE. 
Florida citrus fruits are subject to two distinct types of tear 
streaking, namely, wither-tip tear-stain and melanose tear-streak. 
The former has been attributed to CoUetotrichum gloeosporioides 
Penz., while the latter, which will not be discussed in this bulletin, 
is doubtless due to a peculiar distribution of the spores of the 
causal organism (PTiomopsis citri Fawcett) in trickling waters. 
.Wither-tip tear-stain is a smooth, more or less brownish discolora- 
tion of the surface which occurs typically in fingerlike patterns 
about one-fourth of an inch in width, extending longitudinally 
toward the stylar or blossom end of the fruit. (PL I.) These 
streaks may or may not be confined to one side of the fruit, and 
frequently they appear to arise in areas russeted by rust mites 
(Eriophyes oleiveros Ashmead). The streaks are usually few in 
number, seldom more than six or eight; occasionally two or more 
merge and form a rather wide discoloration, in which event the 
injury is generally attributed to rust mites. (PI. II, fig. 1.) 
Wither-tip tear-stain as it occurs in Florida is one of the minor 
diseases of citrus fruits, and for that reason it has received little 
attention from investigators. Its effects are principally observed 
on the round orange and grapefruit, more noticeably and frequently 
on the latter and to a less extent upon other economic species of 
citrus. 
15580°— 21- Bull. 924 
