CELERY LEAF BLIGHT 317 



which prevents the spores germinating on the leaves. 

 The fruit-bearing branches of the fungus come through 

 the stomata of the leaf and produce spores on the surface. 

 When the greater part of the foliage is thus destroyed, the 

 crop is a failure. 



PREVENTIVE MEANS. Spraying with an ammoniacal 

 carbonate of copper solution has been proved to be 

 effectual in checking disease, but it is very important to 

 commence quite early, as the plants are most susceptible 

 to the disease when quite young. 



Professor Galloway states that spores found on frag- 

 ments late in spring germinated readily, hence all dis- 

 eased leaves should be collected and destroyed. 



Galloway, Ann. Rep. Commis. of Agric., U.S., 1886, i pi.; 

 also in Rep. 1888, p. 398. 



Halsted, N. Jersey State Ag. Expt. St. Rep. 1891, 

 p. 250, fig. 



SHOT-HOLE FUNGUS' 



(Cercospora circumscissa, Sacc.) 



This well-known pest attacks the leaves of peach, apricot, 

 cherry, almond, and nectarine. Small circular patches of 

 the leaf, bearing conidia on one or both surfaces, become 

 dry, contract, and drop away, leaving a hole in the leaf; 

 numerous such holes are often present on a single leaf, 

 giving it the appearance of having been riddled with small 

 shot. Such diseased leaves fall early in the season before 

 the formation of wood has been completed, consequently 

 there is a poor crop of fruit the following season. The 

 young branches, and even the fruit of the peach, are some- 

 times attacked. The disease often spreads quickly, being 



