abstracts: phytopathology 121 



PHYTOPATHOLOGY.— nc anthracnose of the mango in Florida. 

 S. M. McMuRRAisr. U. S. Department of Agriculture Bulletin 52, 

 pp. 15. 1914. 



An investigation of the mango anthracnose or blight was conducted 

 in Florida during the seasons of 1912 and 1913 ^\^th a view to deter- 

 mining (1) the cause of the disease, (2) the control of the disease, and 

 (3) the broader question of the suitability of the southeast coast of 

 Florida for the production of the mango on a commercial scale. 



Infection experiments by the \M'iter and others have shown that the 

 blighting of the mango blossoms, the tear staining and scabbing of the 

 fruit, and the spotting of the leaves is due to Colletotrichum gloeospor- 

 ioides Penz. 



The experiments on the control of the disease indicate that the blos- 

 som bhght form of the disease cannot be controlled by spraying with 

 Bordeaux mixture during seasons which are rainy at blooming time, 

 but that the fruit may be protected from fungus invasions and carried 

 through to maturity in a clean and disease-free condition b}^ spraying. 



In regard to the third proposition, observations in Florida indicate 

 that a set of fruit cannot be expected unless the weather is dry at bloom- 

 ing time. This coincides entirely with the opinions expressed by writ- 

 ers on the mango from Porto Rico, Jamaica, and Hawaii, and forces 

 the conclusion that the main limiting factor of the mango is the condi- 

 tion of the weather at blooming time. Given clear, dry weather, a 

 good crop of fruit may be expected. Given, on the other hand, rainy 

 weather at blooming time, i.e., suitable conditions for fungus infection, 

 a failure is practically certain. 



The main bloom of the mango occurs in March. The weather rec- 

 ords for Miami show that the months of March in 1912 and 1913 were 

 unusually rainy, but that the mean mrniber of rainy days for March 

 based on a record of 16 years is only 4.56 days, and that in 8 years out 

 of the 16 the number of rainy daj's fell below this mean. From this 

 it would appear that the chances for success are quite good, the hazard 

 being probably no greater than in most of the peach growing sections 

 of the Xorth.^. S. M. M. 



PHYTOPATHOLOGY. — Polyporus dryadeus, a root parasite on the oak. 



W. H. Long. Journal of Agricultural Research 1: 239-250. 1913. 



A brief history is given of this fungus since Bulliard first described 



it in 1789 as Boletus pseudo-igniarius. Attention is called to Hartig's 



