STATE POMOLOGICAL SOCIETY. 103 



Six pounds of sulphate of copper was crushed and dissolved in ten 

 gallons of water ; four pounds of fresh lime was then slaked in six 

 gallons of water in another vessel. When the solutions were cool, 

 they were put into a barrel and thoroughly mixed. 



The mixture can be applied with a Japy, or Eureka pump and the 

 improved Vermorel lance and nozzle, or any other suitable spraying 

 apparatus. 



THE BLACK- KNOT OR PLUM-VTART PLOWRIGHTIA MORBOSA, SACC. 



This fungus was described over sixty years ago by the noted bot- 

 anist, Dr. Schweinitz. The nature of the fungus was quite well 

 known at that time, at least the appearance of the excrescences and 

 the cause of them was recognized. The nature of the reproductive 

 organs, the conidia, stylospores, ascospores and pycnidio-spores 

 were made known by Dr. Farlow, but how these spores produce 

 new knots has never been observed. From analogy it is thought the 

 spores are carried by the wind, and, lodging on the branches, ger- 

 minate and find entrance. There is need of careful study of the 

 early stages of the knots and the means of infection. The fungus is 

 probably perennial and not dependent upon the spores. The myce- 

 lium lives in the wood over winter and extends the knot the next 

 season. The spores that find entrance develop into knots the next 

 season. The summer spores begin to be formed in the spring, and 

 continue to appear during the summer. The winter spores are ripe 

 by February. The disease affects the plum, morello cherry and 

 some of our wild cherries. The disease is confined to America, not 

 occurring in Europe. In this country it has, with the curculio, 

 about caused plum raising to be abandoned. 



To devise means of destroying this fungus and restore plum rais- 

 ing is of great importance. There have been several remedies pro- 

 posed and some interesting experiments have been tried the last 

 season at the Massachusetts Agricultural Elxperiment Station. 

 Below we give some of the remedies, preventive, protective and 

 direct, that have been tried. 



REMEDIES. 



1. Cut the diseased branches and burn them. (Care should be 

 taken to cut enough wood to include the mycelium. If the tree is 

 hopelessly involved, it should be destroyed at once. Burning is 

 necessary, as the spores are produced on detached branches. The 



