CERTAIN INSEC7 AND FUNGOUS PESTS. 



417 



the leaflet may be attacked only in one spot, which, con- 

 tinuing to enlarge, causes the whole to become brown 

 and lifeless, followed by a torn condition. Two or three 

 of these large, dead, shredded places may be all that the 

 leaf contains, while the bal- 

 ance is healthy and deep 

 green. 



"Experiments have not 

 yet been made upon this 

 leaf-spot fungus, but it is 

 probably true that the 

 same remedy as that used 

 for the ordinary leaf-blight, 

 and applied in the same 

 manner, would prove effec- 

 tive. It will be important 

 to begin early with the 

 spraying. 



While looking for specimens of the phyllosticta pre- 

 viously mentioned, a blight was found in considerable 

 quantity that proved to be a septoria. The appearance 

 of the blighted leaves is shown in figure 2. This disease 

 differs from the others, to the naked eye, in the more 

 complete killing of the leaf affected. It has been shown 

 that the cercospora gives a spotted appearance, while 

 the phyllosticta produces an occasional large patch that 

 is dark brown and dead. The blight now under consid- 

 eration often causes the whole leaf to become brown, 

 with small black dots over the surface. In a plant at 

 all affected the whole foliage is likely to be diseased. 



Fig. 3.— Portion of Leaf Af 



FECTED WITH CELERY-RUST. 

 CPuccima bullata, Wint.) 



Fig. 4.— Portion of Leaf Affected with Celery Bacteria. 



'The celery-rust proper {Pitccinia bullata [Pers.], 

 Wint.) has not yet appeared in this country, but is found 

 abundantly throughout Europe and elsewhere. Figure 3 

 shows a leaflet with the rust-spots. 



A peculiar blight was recently found in the celery 

 fields near Greenville and Bayonne, France, particularly 

 on the Golden Plume variety. The affected leaves were 

 badly blotched with brown. It proved to be a bacterial 

 disease. The appearance of a diseased leaf is shown in 

 figure 4. All the dark portion abounds in germs. A 

 central portion of a celery-plant with its heart infested 

 and one of the outermost leaf-stalks decayed and fallen, 

 is shown in figure 5. 



" It was observed that the bacteria increases most rap- 

 idly when the celery is kept constantly moist but not sub- 

 merged. Thus, stalks placed 

 partly under water to which 

 germs had been added decayed 

 quickly near the surface, while 

 the portion submerged was the 

 last to spoil. The practical 

 lesson from this is to keep the 

 celery dry or else place it 

 under pure water. That this 

 disease is serious may be 

 judged from the fact that a 

 large grower has lost nearly 

 his whole last crop, the heart 

 of each plant melting away to 

 a worthless mass of rottenness. 

 The same trucker has lost a 

 large per cent, of his carrots 

 from bacterial decay, and this 

 suggests the probable connec- 

 tion between the two. The 

 spraying that has proved ef- 

 ective against the blight will 

 doubtless check the bacteria if 

 applied at the proper time. 



"Weekly spraying with the 

 ammoniacal carbonate of cop- 

 per will probably prove effec- 

 tive for all the diseases of the celery, and wherever grow- 

 ers have had blight or" rust " they are encouraged to try 

 the same remedy or some other good fungicide." 



NEW POINTS ABOUT POTATO DISEASES. 



Of the numerous fungi known to attack potato-vines, 

 only one, the fungus which causes blight and rot, Fhy- 

 tophthora infcstans (De Barry), appears to have been 

 considered worthy of general attention. As it is often 

 quite destructive growers have learned to fear it, with- 

 out imagining, however, that there are other fungous 

 enemies of the crop which have become almost as 

 troublesome as the phytophthora. 



Personally we are but slightly acquainted with the 

 ter, and therefore have less fear of it than of another 

 form of blight which has given us much trouble for a 

 number of years, and which has eluded all efforts to 

 identify it. Our first acquaintance with it dates from 

 1887 or 1888, when our crop (in New Jersey) was badly 

 affected, and the yield cut down one-half in consequence 

 of the attack. Since then our potatoes have suffered 

 more or less from this same blight every year, and we 



CORE OF CELERY- 



\nt Destroyed by 

 Bacteria. 



