VEGETABLE AND FIELD CROPS 295 



scattered pycnidia.^ The tissue within is spongy, moist, 

 and from ohve-gray to green in color. In the United 

 States the disease was first noted in Louisiana on po- 

 tatoes received from Java. It has also been noted in 

 Florida. 



Scurf (MonilochcBtes infuscans Ell. & Halst.). — A brown 

 or rusty coat often forms over the whole potato. It 

 causes no decay, but does result in shrinking, loss of 

 volume, and unsighthness, which may reduce the money 

 value of the crop a half dollar per barrel. The same affec- 

 tion occurs upon the roots from which the potatoes arise, 

 but seems to do little or no damage there. 



Blue mold, penicilliose {Penicillium sp.). — The diseased 

 parts are of. almost chalky color and consistency, dry and 

 inoffensive. Until the root is cut this rot may escape 

 observation. It may be first seen as a sUght depression 

 in the roots at the base of a fine fiber. These depressions 

 enlarge and deepen and may involve the whole potato. 

 In sections of these spots the diseased portion is found to 

 have a dark border which upon exposure to the air 

 rapidly changes to a dark olive color. 



Leaf spot, leaf blight, phyllostictose {Phyllostida bata- 

 ticola Ell. & Mart.). — Spots of dead tissue from 1-10 mm. 

 in diameter are frequent upon the leaf. They are some- 

 what angular, very definitely bordered, and bear numer- 

 ous pycnidia, visible to the naked eye. In many instances 

 these spots become so numerous as to cause the whole leaf 

 to yellow and fall and thus seriously interfere with starch 

 production, and lessen the crop. 



Spraying with Bordeaux mixture would probably stop 



' Clendenin, Ida, Bot. Gaz. SI, 92, February, 1896. 



