Vegetable and Field Crops 



175 



estimated in California in 1908; in Michigan in 1915 a loss of 

 more than a million dollars. A cut in price of 5 to 10 cents 

 per crate is common when the bunches are only slightly 

 disfigured. The disease occurs on celery, also on parsnip and 

 parsley. 



In its early stage it consists of leaf spots; in later stages, 

 the infection of the leaf becomes general, numerous black 

 pycnidia are scattered upon all parts and even upon the 



Fig. 95. — Celery leaf infected with Septoria. After Coons. 



blanched petioles. In extreme cases wilting of the leaves and 

 destruction of the plant follows. After the celery is put in 

 storage the disease may still progress and do great damage, 

 rotting off the leaves and forcing early marketing. Late- 

 blight is often found in the seed bed, and is probably carried 

 by the seed, since the pycnidia are abundant upon the seed- 

 ing stalks and fruit. 



Seeds should be disinfected and the seed bed rotated. If 

 the disease has been troublesome in preceding years, the 



