FUNGOUS DISEASES 259 



Remedy If the trees are sprayed with the bor- 

 deaux mixture (4:4:50) as per spraying calendar of 

 the stations, this fungus will be kept under control. If 

 any warts appear they should be cut off and burned in 

 the winter or spring before growth begins. 



Shot-hole Fungus (Cylindrosporium padi) (Sep- 

 toria cerasina Peck) This fungus attacks all of the 

 plums, and in very moist seasons is very destructive 

 unless the trees are thoroughly sprayed. It first 

 appears as small red spots in the leaf which soon in- 

 crease in size and. turn brown. After a time the 

 brown part of the leaf drops out, leaving small holes, 

 which gives the name to the disease. 



Remedy Spraying as for the last named fungi. 



Leaf Rust (Puccinia pruni-spinosa) In its effect 

 upon the tree and in general appearance this fungus 

 is very much like the last; the spots, however, are 

 smaller and as a rule, more numerous, and cause the 

 leaves to fall in the same way. In some sections of the 

 country it is more prevalent than the shot-hole fungus 

 and in others less so. Both are readily controlled by 

 spraying as above described. 



Plum Pockets, Plum Bladders (Exoascus pruni) 

 This fungus attacks the fruit while young, causing 

 it to swell until it often reaches full size in a few days, 

 first light green or yellow, then as the spores develop 

 on the outside, it assumes a grayish color and 

 then a dark brown. The American varieties are more 

 subject to its attack than are the European or the 

 Japanese. 



Remedy Spraying as for the last two fungi will 

 be found effectual in keeping this pest in check. 



Brown Rot (Monilia fructigena) See under the 

 peach. 



Powdery Mildew (Podospliaera oxyacanthae) See 

 under the apple. 



