CELERY 2 I I 



to 32 F. and should be maintained at that point throughout the 

 storage period, which from the nature of the crop is short. The 

 length of the storage period for celery cannot be extended beyond 

 three months, and the greater part of the product must be removed 

 in sixty days or less. The extension of the marketing period by 

 means of cold storage is, however, of great value to the industry 

 and to the trade. 



Insects and diseases. The difficulties encountered in celery 

 culture are of three kinds: (i) physiological troubles; (2) insect 

 pests ; and (3) diseases. 



Physiological troubles. Physiological troubles are usually due to 

 one of two causes poor seed or improper handling of the young 

 plants. Poor seed can be guarded against only by the purchase of 

 the best stock from the most reliable dealers. Poor 'seed, as a rule, 

 manifests itself by the running to seed of the plants the first year, 

 and in pithy stalks. Since both these conditions may be brought 

 about in other ways, it is necessary to consider cultural conditions 

 carefully before charging such shortcomings to the seed. Adverse 

 conditions in the field or seed bed which give the plant a severe 

 check, followed by conditions which stimulate growth, often result 

 in the plants shooting to seed ; the same causes may also produce 

 pithy stalks. 



Insect pests. Celery is remarkably free from harmful insect 

 enemies. The zebra caterpillar (Papilio polyxenes Fab.) is the 

 larva of a moth which deposits its eggs upon the celery, and 

 sometimes feeds upon the leaves in sufficient number to necessitate 

 hand picking or the use of arsenical sprays. 



Diseases. Celery blight (Cercospora apii) is the one great dis- 

 ease with which the commercial celery grower has to contend. 

 This disease causes the leaves of the plants to lose their normal 

 color, turn yellow, and finally brown, after which decay sets in. 

 This is not confined to the crop in the field but attacks the 

 young plants in the seed bed. Fortunately it yields to treatment, 

 but eternal vigilance is the price of a clean crop. To secure 

 a clean crop the treatment should begin in the seed bed. The 

 young plants, if sprayed with Bordeaux mixture every ten days or 

 two weeks, the interval depending upon the weather, can be pro- 

 tected from the disease. Good care in the seed bed means clean 



