304 DISEASES OF CROP-PLANTS 



death. Johnston and Stevenson attribute some importance to 

 the infestation of cuttings. 



Description. 



The first external sign of the occurrence of the fungus is a 



Fig. 122 

 Thielaviopsis paradoxa, Sporophores of Micro- and Macro-conidia 



From Wakker & Went 



browning of the surface, which is accompanied by souring and 

 reddening of the interior tissues. Numerous small pustules 

 appear just beneath the rind. The pustules open and from each 

 is extruded a black thread which under some conditions becomes 

 long and curly, in others settles into an irregular heap ; it is made 



