BOTRYOSPHAERIA ON COTTON BOLLS 



C. W. Edgerton 



Among the fungi of minor importance on cotton bolls in the 

 southern states is a pyrenomycete whiph has been provisionally 

 referred to Botryosphaeria fuliginosa (Mongeot & Nestler) Ellis 

 & Ev. This fungus is not common on cotton but is occasionally 

 picked up. The first collection on this host seems to have been 

 made by Atkinson in Alabama some years ago. Atkinson's 

 material was sent to Massee and was determined by him as 

 Botryosphaeria Berengeriaiia De Not.^ But as Ellis and Ever- 

 hart list this name as a synonym of Botryosphaeria fuliginosa, the 

 latter name will be used in this article. It is probable that this 

 name is not the correct one, but the question of nomenclature 

 will not now be considered. Atkinson's material has also been 

 examined by the writer and found to be identical with material 

 collected by him. 



Having found this pyrenomycete on cotton bolls in Louisiana, 

 a study of its life history was commenced in order to see if it had 

 any connection with any of the imperfect fungi which are instru- 

 mental in causing boll rots. On account of the somewhat similar 

 appearance of the boll afifected by the Botryosphaeria, to one 

 afifected by Diplodia gossypina, it was thought that there might 

 $ be some connection between the two. This seemed all the more 

 possible because Shear had reported Sphaeropsis and Diplodia 

 forms as connected with Botryosphaeria.- However, this was 

 not found to be the case. While the Botryosphaeria on cotton 

 bolls has an imperfect form in its life history, it is quite distinct 

 from Diplodia gossypina. 



Two stages of the fungus have been found, a pycnidial stage 

 belonging to the form genus Macrophoma, and the perfect or 



^ Atkinson, G. F., Some fungi from Alabama, Bull. Cornell University, 

 3: II- 1897. 



- Shear, C. L., Life History of Melanops Quercnum (Schw.) Rehm forma 

 Vitis Sacc. (abstract), Science, n. s. 31 : 748. 1910. 



34 



