Mar. 4, 1918 



Wilt Diseases of Okra 



535 



size of 10 normal triseptate conidia, 32.5 by 4.6 fx. One-septate conidia, 

 20 per cent. Abnormal conidia and microconidia, 20 per cent. 



Normal conidia on rice culture 2H months old: Triseptate, 23.8 to 

 30.0 by 4.0 to 5.0 IX. Five-septate rare, 56.0 by 3.6 fx. 



F. vasinfectum strain 3203 from okra. Pionnotes on a 25-day-old 

 stem culture of MeliloUis alba. Limits of size of 28 normal triseptate 

 conidia: 23.8 to 34.0 by 3.8 to 4.2 tx. Average size, 28.4 by 3.9 /u. 

 Largest triseptate conidium, 34.0 by 4.2 fx. Smallest triseptate coni- 

 dium, 23.8 by 3.8 (x. 



F. vasinfectum strain 3242 from okra. Normal triseptate conidia, 

 34.0 to 41.0 by 3.4 to 5.0 fx. Four-septate conidium 40.8 by 4.2 [x. 



F. vasinfectum var. inodoratum strain 3257 from okra. Thirty-four- 

 day-old Meliloius stem culture with pionnotes. Normal triseptate coni- 

 dia 60 per cent. Limits of 17 spores, 32.3 to 45.9 by 3.4 to 4.8 /x. Aver- 

 age, 37.4 by 4.2JU. Four-septate, 35 per cent. Limits of 13 spores, 34.0 

 to 44.2 by 4.2 to 4.8 fx. Average, 39.0 by 4.2 m- Five-septate, 5 per 

 cent. Limits of four spores, 37.4 to 45.9 by 4.2 to 4.9 /u., average four 

 spores 42.0 by 4.4 m- 



F. vasinfectum var. inodoratum, strain 3258 from okra. Thirty-four- 

 day-old pionnotes culture. Normal triseptate conidia 76 per cent. 

 Limits of 9 spores, 27.2 to 41.6 by 3.4 to 4.6 /u. Average, 34.o»by 

 4.2 ju. Four-septate conidia, 19 per cent. Limits of 13 spores, 35.7 to 

 42.5 by 3.4 to 5.0 IX. Average, 37.8 by 4.1 ix. Five-septate, 5 per cent. 

 Limits of 6 spores, 34.0 to 45.9 by 3.8 to 4.7 ix. Average, 40.0 by 4.2 /u. 



Parallel cultures of F. vasinfectum, strain 1855, from cotton and strain 

 3592 from okra were prepared upon cotton stems as a medium. At the 

 age of 45 days, 50 normal triseptate conidia from a pionnotes of each 

 culture were measured to obtain the relative sizes. The maximum 

 minimum, and average length and width of conidia in each culture are 

 shown in Table IL There is a close correspondence of the measurements 

 of conidia from the two strains, considering that these measurements 

 were made from but one culture of each strain. 



Table II. — Comparative size of normal triseptate conidia of Fusarium, vasinfectum from 



okra and cotton 



Maximum length. 

 Minimum length . 

 Maximum width. 

 Minimum width . 

 Average length . . . 

 Average width . . . 



F. vasinfectum 



1855 from 



cotton. 



5-1 



3-4 



37- o 



4.2 



F. vasinfectum 



3592 from 



okra. 



44. 

 27. 



5- 

 3- 



35- 

 4- 



