152 



MAINE STATE COLLEGE 



mm 



BOTANY. 



Bean Anthracnose. 



Golletotrichium Lindemuthianum, (Sace & Magn ) Briosa & Cavara. 



The above disease of the bean has befn quite 

 common in gardens and fields about Orono for the 

 past seven years and we presume it is prevalent 

 throughout the State. It was unusually bad the 

 past season, and specimens were received from dis- 

 tant localities and inquiries made regarding it. It 

 is probably the worst disease of the bean and as its 

 ravages can be largely controlled by proper precau- 

 tions and treatment, the following consideration of 

 the fungus may prove helpful in combating it. The 

 Bean Anthkacnose is a parasitic fungus attacking 

 the stem, leaves and pods of both bush and pole 

 beans, producing, especially on the pods, sunken 

 brownish pits or spots surrounded by a reddish 

 brown border. See Fig. 1. In the central part of 

 these pits are little pinkish dots which are the spore 

 masses that have exuded from below. The spores 

 are held together by a gummy substance that is 

 soluble in water and they may be liberated by dew 

 or rain or excessive moisture and then are free to 

 be blown by the wind to healthy plants, where they 

 germinate and spread the disease. The disease is 

 worst upon the white podded bush and pole beans 

 fig. i— Bean An- but will also attack the more hardy varieties. The 

 saowingpits° d past season it was quite bad upon yellow eyes in 

 disease (original) the field. We lost the greater part of our garden 

 crop of German Wax the past season, the pods becoming so covered 

 with pits before they were large enough to pick as to be worthless. 

 The effects of this disease are to lessen the stand when it destroys 

 the seedlings ; to dwarf the plants and make the pods swollen and 

 when it spots the pods to render them unfit for snap beans, also to 

 finally injure the bean in the pods. This disease may originate 

 from infected seed or, wej think, it may live over winter in the 

 beans and pods that are left in the garden. When'infected seed is 

 planted the disease shows itself early in the seedlings. Much of 

 the seed of German Wax beans offered for sale is infected. The 

 past season fully half of the seedlings in our garden were affected 



