BULLETIN OF THE 
No. 52 
Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief 
January 24, 1914. 
THE ANTHRACNOSE OF THE MANGO IN FLORIDA. 
By S. M. McMurrax, 
Assistant Pathologist, Fruit-Disease Investigations. 
INTRODUCTION. 
The growing of mangos in Florida is beginning to assume some 
commercial importance. With the increase in size and value of the 
crops, the mango blight or anthracnose has forced itself upon the 
attention of the growers and a demand has arisen for remedial or 
preventive measures. The writer was assigned to the investigation 
of this disease and spent the .seasons of 1912 and 1913 in Dade and 
Palm Beach Counties, Fla., studying the trouble in the field and 
laboratory. 
A careful canvass of the situation was made during the last week 
of January and the first week of February, 1912, and all the trees and 
groves that could be located between Key Largo, 40 miles south of 
Miami, and Palm Beach, 70 miles north, were examined. It was 
found that practically all of the seedling trees had bloomed heavily 
during the first two weeks in January, but that none had set fruit. 
Most of the trees carried the dried peduncles of the January bloom 
at this time, and many of them remained attached to the trees until 
the middle of March, at which time a second crop of bloom appeared. 
Several hundred of these peduncles were collected and many of 
them while still on the trees showed spores of a fungus in abundance. 
A number of those that did not show spores were placed in a moist 
chamber and they all developed spores of the same type in from 
24 to 48 hours. At the same time a number of leaves showing small, 
irregular, grayish spots were collected and placed in moist chambers. 
In from three to four days these leaves produced similar spores in the 
diseased areas. Later in the season young shoots that showed black 
spots were collected and placed in moist chambers. These also 
produced the same type of spores from the diseased spots. In the 
latter part of June, as the fruits were ripening, a number were col- 
lected, the skins of which were blotched and disfigured, and these 
likewise produced the same type of spores. (PI. I.) Portions of 
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