406 AGRICULTURE OF MAINE;. 



takes place in one to two weeks. The tissues become soft and 

 are light brown in color. Little tufts of mycelium which bear 

 the spores break out on the surface of the decayed region as 

 shown in Fig. 70. These tufts soon become light blue or blue- 

 green, later gray-green to brownish in color. Apples rotted by 

 Pcnicillium take on a characteristic moldy odor and taste. 



Since the fungus enters the apple through wounds, any means 

 of control of the rot must look to the prevention of injuries to 

 the epidermis. Care must be taken to produce good, sound ap- 

 ples and then these should be picked and handled in such a way 

 as to avoid cuts and bruises. The apples should be stored 

 where the temperatures are as low as can be maintained with 

 safety from freezing. 



Bitter rot. This disease which does so much damage in some 

 apple growing regions is caused by Glomorclla rufomaciilans 

 (Berk.) Sp. & von Sch., and is found occasionally in Maine, but 

 its occurrence is so rare that it is not necessary to recommend 

 special means for its control. Moreover it does not seem that 

 bitter rot will do great damage under Maine climatic conditions 

 if the recommendations with regard to the removal of cankers 

 and spraying are followed as are given for the black rot fungus. 

 Where bitter rot is prevalent spraying later in the season is nec- 

 essary. Fig. 71 shows the appearance of this rot. The fungus 

 found here differs in certain characteristics from the form de- 

 scribed from farther south ancV there is some evidence from our 

 inoculations that it is not so actively parasitic. 



Brozvn rot. The brown rot of the apple is caused by 

 Sclerotinia fructigcna (Pers.) Schroet., the same fungus which 

 causes the destructive brown rot of peaches and plums. This 

 decay of apples occurs to some extent in ^Maine and in some 

 cases may do considerable damage. The fungus spreads 

 through the apple rapidly and in the early stages the surface of 

 the decayed region is smooth and brown. Later little tufts of 

 fungus threads break out on the surface of the apple and these 

 produce the spores as shown in Fig. y2. Often when this rot 

 takes place in storage, away from the light, the tufts of spores 

 do not break out on the surface and the skin assumes a shiny 

 black color. The apples become shrunken and wrinkled as they 

 dry and in some cases these mummied apples hang on the trees 

 over winter. It is these mummied apples which carry the fun- 

 gus over from one year to another and for that reason all de- 



