Calonectria crotalariae

(Loos) Bell & Sobers D. K., (1966)

- classification: Fungi, Ascomycota, Sordariomycetes, Hypocreomycetidae, Hypocreales, Nectriaceae
- synonym: Cylindrocladium crotalariae (Loos) DK Bell & Sobers, (1966)

Root systems infected by Calonectria crotalariae are reduced in size. Large black lesions are found at the collar. The cortex shows deep splits in several locations.

This fungus produces numerous  microsclerotia in diseased tissues. It has been reported on tobacco predominately in the USA; however it appears that tobacco is not a preferred host for this pathogen.  It does not occur in France on Solanacea family. 

Avoid growing other hosts of the pathogen, such as peanuts and soybeans, in rotation with tobacco.