106 Mortier F. Barrus 



Economic importance 



While bean anthracnose can be found on some plants year after year, 

 it is only during certain periods most favorable for its development that 

 it becomes widespread and causes serious loss. Such epiphytotics are 

 coincident with or closely follow periods of rather abundant rainfall 

 during the growing season, and often recur in three or more successive 

 years. Frank (1883 b: 512), as already noted, reports such an epiphytotic 

 in Germany in 1882, Querner (1908) reports one in 1908, and Fischer 

 (1919:246) reports epiphytotics in 1915 and 1916. Voglino (1892) reports 

 a complete destruction of the crop in 1891 in several localities in Italy. 



Beach (1892:308) reports a heavy loss in many sections of New York 

 in 1891. Halsted (1893-1901) reports the disease as common from 1892 

 to 1897, after which it was an unimportant factor in his experiments. 

 Whetzel (1908:436) reports the disease as widespread in New York in 

 1906. Then followed five years during which the loss in most sections 

 of the State was negligible. Late in the season of 1911, the disease was 

 observed or reported from many fields, and in 1912 it was again severe. 

 The following year there was very little anthracnose to be found except 

 in restricted areas, but it was present to a destructive degree in 1914 

 and 1915, the loss during the latter year ranging from 30 to 100 per cent 

 of the crop except in a few cases where resistant varieties were grown. 

 During 1916 the damage done in this State was slight, but the disease 

 appeared again from 1917 to 1919, the losses in these years, however, 

 being much less than in earlier years. 



A study of the table given in the Plant Disease Survey bulletin (page 

 254 of the reference already cited) shows that bean anthracnose was 

 generally severe in the eastern United States from 1906 to 1908, from 



1914 to 1915, and again in 1917. Individual reports of its severity are 

 recorded in other years. In Maine and New Hampshire it is reported 

 as causing considerable loss nearly every year, while in Western States 

 it rarely does any damage although it may be present. 



Figures are not obtainable to show the exact loss from this disease, 

 but in epiphytotic years it is very large, amounting in individual cases to 

 100 per cent. Muncie (1917:7) estimates a loss in Michigan of $1,500,000 

 in 1914 and of about $3,000,000 in 1915, while the loss in New York in 



1915 probably amounted to $700,000 or more. The Plant Disease Survey 



