VEGETABLE AND FIELD CROPS 255 



stalks which would otherwise stand, and aids in rapid 

 rotting. 



Treatment against other diseases and maintenance of 

 the plants in full vigor is of most service in this case. 



Black mold (Macrosporium Porri Ell.). — This black mold 

 much resembles the last, but its spots are somewhat more 

 pale and usually more definite, less diffuse, and less liable 

 to induce rotting. It does not habitually associate with 

 the downy mildew, and is more truly saprophytic than the 

 black mold above mentioned. While usually upon the seed 

 onions, it is sometimes found upon market onions. 



The treatment suggested above applies here. 



Damping off. See p. 60. 



PARSLEY 



Sclerotiniose, drop, crown rot (Sclerotinia Libertiana 

 Fckl.). — Parsley in the greenhouse is sometimes affected 

 with this disease, which is identical with the lettuce drop. 



PARSNIP 



Leaf spot (Cercospora Apii Fr.). — This is the most 

 common disease of the parsnip, occurring as a leaf spot 

 similar to that upon celery, and caused by a very similar 

 fungus. 



PEA 



Spot, ascochytose (Ascochyta Pisi Lib.). — Spotting of 

 the pea leaves and pods has been known to farmers for 

 many years. It is most conspicuous upon the pods as 

 circular, somewhat sunken spots, 3-6 mm. in diameter, 

 which are dark bordered, pale in the centers, or, when 



