DISEASES OF COFFEE 231 



what manner remains as yet unknown. Spore-formation of any 

 kind has not been observed, but from the presence of clamp- 

 connections in the hyphas the fungus is believed to be a Basidiomy- 

 cete. 



Good results have followed the use of Bordeaux mixture. 

 The fallen leaves and berries should be collected in heaps and 

 burned. The disease is at present confined to plantations along 

 the Surinam River, and is especially severe on an estate on the 

 upper river. It has not been detected in the field on Robusta, 

 Uganda, or Surinam coffee, though infections were secured on 

 these by artificial means. Abeokuta and Excelsa are very 

 susceptible. 



Stahel has also described another disease of Liberian Coffee 

 in Surinam showing a chronic or an acute phase of wilt. The 

 precise cause is not known, but degenerative changes in the 

 sieve-tubes of the inner bast have suggested to him that the 

 disease is in the nature of a phloem-necrosis like the well-known 

 leaf-roll of the Irish potato. 



RosELLiNiA Root Disease. 



Thread Blights. )■ See General Diseases. 



Algal Disease. 



