Plant- Diseases . 



55 



Plum, continued. 



Plum Pockets or Bladders {Taphrina pruni, Tul.). — Causes 

 the fruit to become inflated and hollow. These " bladders " 

 begin to appear soon after the flowers fall, and continue to 

 grow for several months, when they fall. They are at first 

 globular, but finally become oblong, often reaching two inches 

 in length. The fungus attacks the fruit of the Chickasaw and 

 American plums, and various species of plum and cherry. 



Remedies. — Destroy the "bladders" before they mature, 

 together with small portions of the wood on which they are 

 borne. Spray before buds expand with strong sulphaie of 

 copper or iron, and follow with copper fungicides. 



Powdery Mildew. — See under Apple. 



Rot or Blight. — See under Peach. 

 Poplar. Leaf-Rust (Melampsora populina, L6v.). — An orange 

 rust attacking, during summer, the leaves of various species 

 of poplar, including the cottonwood, balm of Gilead, etc. 



Remedies. — Rake and burn the leaves. Spray with copper 

 compounds. 



Potato. Potato-Rot or Blight (Phytophthora infestans, DeBary) . 

 .The spores first germinate upon the tops or vines, causing 

 the foliage to blight. The disease soon spreads to the tubers, 

 causing discolored and diseased potatoes. It is a " dry rot." 

 The fungus may remain in the tubers during winter. 



Preventive. — Plant on light or loamy, well-drained soil 

 Plant only sound and disinfected tubers. Hill deep. 



Remedy. — Spray the tops with Bordeaux mixture, or other 

 fungicide, upon the first indication of the blight, and make 

 three or more applications at intervals of ten days or two 

 weeks. 



The tubers should be stored in a cool and dry place. Dust- 

 ing them in the cellar with dry air-slaked lime is to be recom- 

 mended. Subjecting the tubers to a temperature of 105° to 

 110° for a few days will destroy the fungus and will not 

 injure the tubers for planting. 



There is another kind of potato blight and rot widely dis- 

 tributed over the country, and due to a germ or bacterium. 

 The leaves curl, the plant droops and finally dies, and the 

 tubers contract a putrid rot. Very serious. No remedy is 

 known. Practice rotation. 



