1919.] FUNGOUS DISEASES OF THE AVOCADO. 133 



TREATMENT. 



The treatment for this disease follows closely that given for the 

 Anthracnose of the mango. Sprayings with Bordeaux mixture must 

 be made continually from the time of flowering until the fruits are 

 mature. The frequency of the application must be determined by 

 weather conditions. The more humid the weather, the greater the 

 number of sprayings necessary. 



If avocados are to be shipped for any distance, it is quite important 

 to send fruits which have been sprayed. Though the skin may seem 

 perfectly sound, the fruit is practically always infected by this fungus, 

 for which the best conditions of growth are given when packed in 

 crates or boxes. 



THE DIE-BACK OF AVOCADOS. 



Avocado shoots dying back are of frequent occurrence throughout 

 the colony, and a microscopic examination has shown that these twigs 

 are infected by the fungus Diplodia cacaoicola, which causes the 

 " die-back " of cacao and rubber. Whether this fungus is able to get 

 into uninjured shoots, has not yet been proved, but it is very probable 

 that it gains entrance into the very young tissues through wounds 

 made by the Anthracnose fungus, and when once in the shoots, grows 

 rapidly down toward the trunk of the tree, killing the shoots for a 

 distance of two or three feet from the tip. 



The same fungus has been known to attack budded avocados, gaining 

 entrance probably through the cuts made in the operation of budding. 

 The same treatment recommended for the Anthracnose will serve to 

 combat this disease. 



