156 The Fruit-Growers Guide-Book 



rise to a new crop of spores that infect the new crop of 

 fruit. 



On the branches this fungus causes the formation of 

 cankers, or areas of dead bark. The fungus is believed to 

 live in these cankered areas for two years, giving rise to a 

 crop of spores which falls onto the fruit, causing the char- 

 acteristic black, decaying areas. 



As a means of preventing damage from bitter rot, one 

 of the first preventive measures should be a thorough ex- 

 amination of the trees while in a dormant condition, and 

 removing all of the branches and limbs which show signs 

 of infestation. All of the mummied fruit which remains 

 en the branches should be removed and burned. Then the 

 trees should be given a thorough spraying with bordeaux 

 mixture. As many as six applications of this mixture will 

 be needed, beginning in the spring, and applying the spray 

 at intervals of two or three weeks until July, and even after 

 that date if bitter rot should appear. Experiments carried 

 on by the Illinois Experiment Station go to show that the 

 early sprayings are more effective in controlling this dis- 

 ease than if the spraying is not done until after the disease 

 appears. The work of spraying should be done thoroughly, 

 so as to coat every fruit and leaf. 



Blotch. This disease occurs through the southern and 

 eastern part of the United States where it causes serious 

 damage to the fruit on several different varieties of apples. 

 On the fruits these blotches appear as dark colored, star- 

 shaped areas, often being so numerous on an apple as to 

 cover the entire fruit. It attacks only the skin of the 

 fruit, so that the continued growth of the underlying tissue 

 frequently causes the fruit to crack. The fungus does not 

 rot the fruit as in the case of bitter rot, but mars the ap- 

 pearance so as to make it unsalable. 



The fungus also attacks the twigs and branches on 

 which it causes the formation of small and rather incon- 

 spicuous cankers. On the rapidly growing shoots and 

 watersprouts these cankers have the same general appear- 

 ance as on the fruit. The fungus lives in the cankers for 



