84 Lessons in Fruit Growing. 



Preventive measures. The disease gains entrance to 

 the flowers through spores that live from year to year. 

 Since every fruit destroyed by the fungus matures millions 

 of spores, every decayed fruit that is permitted to hang on 

 the tree until the following spring is a source of infection 

 to the next crop. As soon as the ripe fruits that escape 

 the rot have been gathered, all decayed ones, whether on 

 the tree or on the ground, should be collected and destroyed 

 by burning or burying. It is wise, also, to rake up and 

 burn the fallen leaves in autumn, and thus destroy all ad- 

 herent spores of the fungus. Spraying the trees with Bor- 

 deaux mixture in early spring, taking care to thoroughly 

 wet the trunk and branches will tend to prevent the ger- 

 mination of spores on the tree, and thus lessen the chances 

 of infection of the flowers. Spraying the fruit at the ap- 

 proach of the ripening period with a solution of potassium 

 sulfide, at the rate of one-half ounce to a gallon of water, 

 also tends to prevent the disease. Early picking of the 

 fruit, provided it is picked quite dry, usually prevents seri- 

 ous damage from rotting. 



Planting and pruning the trees with reference to secur- 

 ing abundant circulation of air among the leaves and fruit, 

 and thinning the fruits so that no two specimens hang in 

 contact, also tends to reduce the rot. 



102. The black knot of the plum and cherry {Plow- 

 rightia [Sph(£na\ viorbosa)is a fungous disease that attacks 

 the younger branches, causing abnormal, dark-colored 

 swellings of the wood, and sooner or later destroying the 

 affected parts. 



Preventive measures. Spraying with Bordeaux mixture 

 has been found to reduce the number of affected branches, 

 but where the disease has secured a foothold, the branches 

 should be promptly cut off and burned. 



