DISEASES OF CULTIVATED PLANTS 385 
But this is by no means a common fact, and in some years there is much blight- 
ing after the celery has been boarded up for blanching. Usually the fungus is 
discoverable in diseased areas of the leaves. The use of fungicides, such as 
Bordeaux mixture, is likely to prove beneficial, especially to protect the plants 
in the seed bed until transplanted. (See Spray Calendar). While beneficial for 
later applications in the field, so long as it is not clear that the fungus parasite 
is not the only cause of blighting or leaf spotting, all possible conditions should 
receive attention. Kinney (Rhode Island Exp. Sta. B. 44) has suggested that 
the breaking down of the celery leaves arises from the methods of culture prac- 
ticed, particularly the level culture, in which the water relations of the plant 
are not in a natural state. He succeeded in preventing the blighting of celery 
by mulching with celery tops in which there was a large supply of the fungus. 
Mulching, especially during periods of prolonged drought, may thus prove 
profitable. The identification of the particular fungus occurring in the spots 
must, in each case, be made by the misroscope. Aside from the mulching sug- 
gested the remedies are stated in Bulletin 121. 
The conditions of celery culture are yearly becoming more troublesome and 
are really serious. 
Fig. 39. Younger celery plants attacked by root-rot. These plants are kept alive by new roots, 
though they increase but little in size. After VanHook, Cir. No. 72. 
Heart-Rot is a very destructive decay of the inner, or heart, portions of the 
celery plant after blanching has begun. The inner parts rot very suddenly, 
emit a penetrating odor and the market value of the affected celery is destroyed. 
