Vegetable and Field Crops 201, 



OKRA 



Wilts ^^^ {Fusariwn vasmfectwn Atk., Verticillium alho- 

 atrum R. & B.). — Two wilts of okra, macroscopically in- 

 distinguishable from each other, occur; both partake of the 

 general character of wilts discussed elsewhere, pp. 26, 253. 



Pod-spot (Ascochyta abelmoschi Hart.) is reported from 

 New York and Maryland, and a Leaf-spot {Cercospora) from 

 Porto Rico. Texas-root-rot (Ozonium) is injurious in the 

 Gulf states. 



ONION, GARLIC, CHIVE ' '' 



Smut 2-^5-257 ^ jjj'ocystis cepulce Frost) . — As with the wilt of 

 tobacco and cotton, this fungus resides in the soil and is 

 therefore destructive not only to the present crop, but is 

 also prohibitive of successful culture of susceptible crops 

 in the future. 



The smut, which seems to have originated upon a wild 

 variety of onion, occurs in both Europe and America. It 

 was known in Connecticut as early as 1860, Massachusetts, 

 Pennsjdvania, and Ohio in 1889, later in New York, New 

 Jersey, and Delaware, and has since been recorded from 

 Iowa and Georgia. The first mention of serious loss by 

 onion smut in America was in 1870. Its inroads upon the 

 crop are often such as to prohibit profitable onion culture 

 unless preventive measures are taken against the disease. 



The smut attacks the very young seedlings through the 

 still tender, delicate leaf sheaths. Onions grown from 

 sets are immune, and onions from seed, if they pass the 

 very young state without infection, are so protected by 

 •hardening of the outer plant parts as to resist attack, even 

 if the bulb is surrounded l^y thoroughly infested soil. 



Upon the infected seedling leaves, dark, opaque spots 

 may be noted, especially upon holding the leaves against 

 the light. The portions of the leaf above such spots soon 

 die, and the spots rupture, exposing sooty, powdery masses. 

 Badly infected seedlings succumb early, while others may sur- 



