THE CELERY LEAF-SPOT 147 



■ with small black dots, projecting slightly above the 

 cuticle of the plant. These dots consist of the spores, 

 or reproductive bodies of the fungus. A leaf injured by 

 this malady is represented in Fig. 63. The black spots 

 appear also on the stems and seeds of the fruiting plant, 

 as shown in Plate XV, and it seems probable that the 

 fungus is disseminated by means of such diseased seeds. 

 The malady commonly appears in the seed-bed, and it 

 is, at least, a safe precaution not to plant seeds so spot- 

 ted. Those who harvest celery seed should not gather 

 from plants so diseased. 



Accounts of this malady occur in report of New 

 Jersey Experiment Station, 1891 (pp. 255-256), and 

 Bulletin 2 ; report Massachusetts Experiment Station, 

 1891 (p. 231) ; and Bulletin No. 51, New York Experi- 

 ment Station. Still another celery leaf fungus, belong- 

 ing to the genus Phyllosticta, has been described by 

 Dr. Halsted. 



Treatment for Celery Diseases. — The most 

 promising method of preventing these celery diseases is 

 that of spraying the young plants with dilute Bordeaux 

 mixture, beginning soon after they come up in the seed- 

 bed, and continuing the treatment at intervals of ten 

 days or two weeks, at least until transplanting time. 

 Later sprayings with either the Bordeaux mixture or 

 the ammoniacal copper carbonate solution, are advisable, 

 if the disease appears in the field. Such sprayings may 

 be made, according to some experiments, up to the time 

 of blanching, without danger of injuring the plants for 

 food, but it would be better, usually, to discontinue the 

 treatment some weeks earlier. Refuse celery should not 

 be left upon the field, especially where the same ground 

 is to be planted to celery the following season. 



