5712 Rerort oF THE HORTICULTURIST OF THE 
the whole center, ‘but frequently the disease appears in blotches 
or strips on some of the tender central stalks and rapidly runs 
down the stem, marking its progress by the soft and discolored 

tissues which have been killed by the disease. Sometimes in the © 
first stages of the disease the watery tissues do not assume a deep 
color till they have been exposed for some time to the air. 
The other trouble mentioned above is manifested in a grayish 
or dark tinge of the affected part frequently accompanied by a 
slight withering or wilting of the leaflets, and watery pimples or 
wrinkles may appear on the otherwise healthy surface of the stalk. 
Finally the diseased leaflets become brown and completely withered 
and the stalk decays. In its first stages this trouble injures the — 
flavor and appearance of the blanched celery and thereby lessens 
or wholly destroys its market value. As before stated it is 
possible that both these troubles are simply different manifesta- 
tions of the same disease, but this has not yet been proved. 
The extent to which conditions of soil may affect the prevalence 
of center blight is not well understood, but it is believed by many 
that center blight is more apt to be serious whenever soil condi- 
tions are unfavorable to thrifty growth of the celery plants; and ~ 
that anything which weakens or checks the growth of the plants 
whether it be leaf blight, lack of available plant food in proper 
proportion, or unfavorable soil conditions, is favorable to the 
development of center blight. Practical experiments must deter- 
mine for each celery grower what is necessary to be done on his 
particular soil to insure the best growth of celery, whether it be 
tile draining, rotation of crops, subsoiling or application of potash, 
phosphoric acid or nitrogenous fertilizers. We can well believe 
that when plants are in the healthiest condition they are best able 
to withstand disease, and, therefore, it is best to secure a healthy — 
vigorous growth of the celery plants. 
Center ‘blight in this section is more prevalent during the hot — 
summer months than in autumn, and, consequently, the early — 
varieties suffer most. The self-blanching kinds are used largely — 
for early celery and this probably is one reason why the disease is é 
reported more commonly on. these varieties. The “green” celery — 
is by no means exempt, but there are some reasons for thinking — 
that, after all, the self-blanching kinds are more susceptible to. 
‘a 

