185 



crops. There are a number of fungous diseases occurring on 

 the apple, some of which are parasitic ; others follow mechani- 

 cal injuries, and still others come about from various causes. 

 The number of diseases affecting our cultivated crops is con- 

 stantly increasing, most of them being introduced from other 

 regions through commercial activities. Some apple diseases 

 have been with us for many years, but just how long it is 

 hard to learn in many cases, although some of the early works 

 on fungi do not refer to them. The early agricultural aud 

 horticultural references are also very meager, and the identity 

 of the disease is often left in doubt. 



Some of the diseases affecting the apple in Massachusetts 

 are given below. 



Rots. 



There are a number of fungi causing apple rots, and those 

 found on the apple in this State are given below. In some 

 sections of the country these rots cause an enormous amount 

 of damage during the summer months, especially in warm, 

 sultry, rainy weather. They are not serious here, usually 

 being found on apples lying on the ground which have been 

 bruised or are in an over-ripe condition, and also on those 

 under poor storage conditions. 



Bitter Rot (Glomorella- rufomaculans (Berl\) Spandl. 

 and von ScJi.). 



This rot (Fig. 1) has been known in this region for many 

 years, and almost invariably attacks the apple on the ground 

 or in storage, although some early varieties are occasionally 

 affected to a slight extent on the tree, especially during warm, 

 muggy weather. It is more serious in the west and south, 

 where it causes an enormous amount of injury to apples. 



The disease is characterized by dark-colored areas on the 

 surface of the apple, which later contain minute, dark-col- 

 ored pustules. These pustules contain smaller and more 

 slender and light-colored spores than those of the Sphcpropsis 

 rot, described below. This as a rule constitutes only about 5 

 or 10 per cent of the apple rots in this section, although in 



