Il6 THE AMERICAN APPLE ORCHARD 



to the development of the chsease, in ahiiost complete 

 destructfon of the crop. 



" 3. Mummied apples which remain upon the trees 

 after the leaves have dropped in the fall should be 

 picked off and destroyed in order to do away with this 

 source of infection during the following summer. 



" 4. Bitter rot cankers upon the branches of the 

 trees, a second source of infection, should be cut off 

 and burned, the limb being cut- a few inches below 

 the cankered spot. Care should be taken not to cause 

 fresh bruises in the bark of other branches while this 

 operation is being performed, and the pruning tools 

 should not be allowed to touch the cankers for fear 

 of carrying the infection to the freshly cut surfaces 

 below the diseased bark." 



Professor Blair is very certain that thorough spray- 

 ing for bitter rot pays in Illinois. His advice, of 

 course, applies with equal force in all sections where 

 the rot is prevalent. 



The Apple Scald — This disease has proved very se- 

 rious in recent years, manifesting itself particularly in 

 the storage houses. It appears on the fruit at any time 

 during the winter, causing it to show a baked or scalded 

 appearance. Though the disease attacks only the sur- 

 face of the fruit, and does not itself injure the culinary 

 quality, it usually opens the way for other agencies of 

 decay, so that when the fruit shows scald it is on the 

 way to rapid deterioration. In fact the appearance of 

 the fruit is so much injured by the scald itself that it is 

 made more or less unsalable, sometimes entirely so. 



The cause of the disease is very obscure. It is not 

 a fungus, nor even a bacterium, but is thought to be an 

 even more obscure agent, which the chemists call an 

 enzym. It can be most closely compared to the trypsin 

 and pancreatin of the stomach and intestines which 



