156 HORTICtJLTUEAL MANUAL. 



before the buds start, using one pound of the copper sul- 

 phate dissolved in fifteen gallons of water without adding 

 milk of lime. When the buds are swelling use the ordinary 

 Bordeaux mixture. When the leaves are fully expanded 

 it is best to use a weaker mixture on all the stone fruits to 

 prevent burning of the leaves. Two pounds of sulphate, 

 two pounds of lime, with fifty gallons of water, has given 

 best results. 



To prevent the show of lime on the fruit of the plum 

 and peach, the last treatment is given with a solution of 

 ammoniacal carbonate of copper (165). 



The treatment for the rot is equally effective in con- 

 trolling the leaf spot or blight which, east of the lakes, 

 often causes the premature dropping of the leaves of the 

 foreign plums, and winter injury to the trees. 



The same treatment also is mainly a preventive of what 

 is known as "plum pocket." This is a disease to which 

 some of the native plums are subject, which causes the 

 fruits to assume the form of enlarged hollow bladders or 

 pockets. But in addition the pockets should be picked 

 and burned and also the swellings found on the leaves and 

 twigs. In the rot of the stone fruits it is also a material 

 aid to pick off and burn the dried fruits that hang on the 

 trees after the leaves have fallen. 



The black knot of the plum and sour cherry is also 

 controlled by spraying as practised for destroying the rot 

 of the stone fruits, with the addition of shaving off the 

 knots as they appear and applying kerosene to the cut 

 surfaces. 



165. Fungi of the Grape and Small Fruits. — The differ- 

 ent forms of rot of the grape, especially in the South, such 

 as black rot, brown rot, and ripe or bitter rot, are con- 

 trolled by a similar system of spraying. The usual plan 

 has been to begin the spraying after the diseases begin to 



