Bean Anthracnose 149 



varieties near by were not affected, but a few years later he found many 

 varieties susceptible. Trelease (1885), in speaking of the "peculiar 

 susceptibility of the white-podded bean," says that " it is not improbably 

 connected with the delicacy of its tissues, which selection has produced." 

 Scribner (1888) states that wax, or butter, beans — those having yellow 

 pods — are the kind most subject to attack, and later (1889) finds that 

 no variety is exempt, not even those with green pods. McCarthy (1892: 

 14) says that wax varieties are especially susceptible. Harvey (1894) 

 finds the disease worse on white-podded bush and pole beans. Cobb 

 (1894:379) says that all varieties of Phaseolus vulgaris are attacked, 

 though the tenderness of the wax (or butter) beans makes them more 

 susceptible. Halsted (1898:312), after growing six varieties of beans, 

 finds Green Flageolet the most susceptible to anthracnose and blight. 

 Whetzel (1906) states that probably all the "rust-proof" varieties placed 

 on the market will spot under conditions most favorable to the fungus. 

 Tracy (1907), in his notes on varieties, records considerable variation in 

 their susceptibility to anthracnose. Jarvis (1908:162) finds that, while 

 wax-podded varieties are more susceptible, some desirable green-podded 

 beans also are affected. Edgerton (1910:49) finds a number of wax 

 varieties with which he has been working to be very susceptible. He finds 

 Valentine somewhat resistant, and Nox All highly resistant on leaves and 

 stems; and he speaks of Hodson Wax as having a reputation among 

 growers for resistance, although he finds it somewhat susceptible. He 

 thinks that observations of the amount of anthracnose on different 

 varieties growing side by side is of little value in determining their 

 resistance, and believes that the only way to test their resistance in a 

 satisfactory manner is to inoculate each variety with the spores of the 

 fungus. Ferraris (1913) lists a few very susceptible and a few resistant 

 Italian varieties. 



The writer (Barrus, 1911) has inoculated a large number of varie- 

 ties of Phaseolus vulgaris. At the time when that work was done, no 

 variety tried proved entirely immune to all cultures. However, it was 

 discovered that there are at least two forms or strains of the organism 

 physiologically different from each other although morphologically and 

 culturally alike. Certain varieties of beans resistant to one of the strains 

 were susceptible to the other, and those resistant to the latter strain 

 were often susceptible to the former. There were other varieties that 



