X V JL-i \^ ^^ 



1 



JOURNAL 



OF THE 



Elislia Mitchell Scientific Society, 



SOME CERCOSPOR.^ FROM ALABAMA. 



BY GEO. F. ATKINvSOX. 



The genu.s Cercospora Fres. conipri.ses a great number 

 of specie.s of leaf fungi producing effects in their hosts fre- 

 quently termed, in common parlance, "blight," or "leaf 

 blight." The species are all probably more or less para- 

 sitic, varying in different degrees of intensity, as obligate 

 parasites, from the forms occurring in dying parts of leaves, 

 languid leaves, upon plants physiologically diseased or of 

 low vitality, induced sometimes by overcrowding and thus 

 preventing necessary circulation of air among the parts or 

 entrance of sunlight; at other times through imperfect 

 assimilation caused by defective drainage, careless prepa- 

 ration and care of the soil, so that the unfavorable physical 

 condition of the soil prevents proper nutrition; by impov- 

 erished soil which predisposes the plant to a hastened and 

 unnatural maturity: to perhaps a few cases of a more viru- 

 lent nature where quite healthy plants are injured from 

 their attacks. 



The nature of this parasitism, in general as above 

 described, would suggest to the thoughtful and progress- 

 ive cultivator of the soil the necessary remedy in each 

 case. 



