FusARiA OF Potatoes 



239 



4-septate, about 28 per cent 



5-septate, about 46.5 per cent, 40 x 4.9 (38-41 x 4.8-4.9) m 

 6-septate, rare, 48 x 5.2fx 

 50. Fusarium discolor Ap. et Wr. var. triseptatiim n. var. (Figs. Iwi 

 and 42; PL iv, figs. 5 and 6; PL v, fig. 10) 



Differs from F. discolor by dominance of 3-septate conidia 24.2 x 4.7 

 (22-26 X 4.5-4.9) M, by presence of very large (up to 1.2 centimeters in 

 diameter), warty, plectenchymic bodies (producing conidia or remaining 

 sterile) of a pale pinkish buff with spots of a darker color, by more intense 

 color of mycelium and substratum (see Plate iv, figures 5 and 6), and by 

 production of larger sporodochia with darker spore masses, much the 

 same as shown for F. culmorum var. leteius in Plate iv, figure 10. 



Hab. On rotted tubers of Solarium tuberosum together with F. coeruleum, 

 Long Island, New York. 



Fig. 42. — Fusarium discolor var. ti-iseptatum. a, Conidia from minute aerial sporodochia 

 from 22-days-old culture on slightly acidified hard potato agar; b, conidia from 66-days-old 

 culture on potato stem plug; c. conidia from aerial mycelium from culture on rye straw; d, conidio- 

 phore from aerial mycelium from 66-days-old culture on potato stem plug; E, conidia from 

 plectenchymic sporodochia, f, conidiophores, from 22-days-old slightly acidified hard potato 

 agar; g, conidia from plectenchymic sporodochia from 9-day s-old culture on hard lima-bean 

 agar; h, basal part of aerial compound conidiophore from 73-days-old culture on red raspberry 

 cane plug 



Measurements of conidia on a few different media are as follows: 

 On slightly acidified hard potato agar, culture twenty-two days old; 

 conidia from minute sporodochia on aerial mycelium: 

 Conidia: 0-septate, rare 



1-septate, 1.6 per cent, 16 x 3.9ju 



2-septate, 6.4 per cent, 18.5 x 4.3 (17-21 x 3.9^.7) m 



3-septate, 91.2 per cent, 22.5 x 4.5 (17-39 x 3.9-5.7) m 



4-septate, 0.8 per cent 



5-septate, very rare, 31 x 5.3 (28-35 x 5.2-5.8) m 



