650 



THE FUNGI WHICH CAUSE PLANT DISEASE 



showed that the mycelium penetrates the seed and may even 

 consume it entirely. 



F. sp. occurs on raspberry.^'* 



F. moniliforme Shel. 



Sporodochium subeffuse, salmon-pink; conidiophores simple 

 or with opposite branches; microconidia continuous, oblong-ovoid, 



Fia. 439. — Fusarium 

 on corn. After 

 Burrill and Bar- 

 rett. 



Fig. 440. — F. vasinfectum. A. Macro- 

 conidia. B. Portion of a hypha. 

 C. A germinating macroconidium. 

 After Reed. 



moniliform, 6-10 n long; macroconidia falcate, acute, usually 

 3-septate, 25-40 ix long. 

 It causes molding of com.*™ 



Several other undetermined species have been isolated from 

 com on which they occur as the cause of dry rot of the grain."" 



A fusarium on banana is by Essed referred to Ustilaginoidella. 

 See p. 214. 

 F. vasinfectum Atk.^*""'*' 



Hyphse at maturity yellowish, 2-4 n in diameter; conidla bome 



singly; microconidia oval, con- 

 tinuous; macroconidia falcate, 2 to 

 3-septate, 1-2 x 2-4 ju. 



Atkinson'*! first described this 

 on cotton and okra in which 

 plants it was found plugging the 

 ducts with its mycelium. The 

 mycelium here was 2-4 n in diameter and microconidia were 

 seen within the ducts. Pure cultures were obtained and inocula- 

 tions with these on plants already injured by Pythium resulted in 



^£^. 



Fig. 441. — F. vasinfectum. D. Mi- 

 croconidia. E. Chlamydospores. 

 After Reed. 



