350 



STATE BOARD OF AGRICULTURE. 



spots which it causes on the mature fruit. In addition to all this it opens a 

 way for the entrance of numerous rot-producing fungi into the tissues of the 

 mature apple. Thus during the seasons of 1902 and 1903. which were character- 

 ized in this state by an unusual rainfall, great quantities of apples were lost soon 

 after packing and in storage and even during shipment through the agency of 

 these soft rots following apple scab. In some cases reported apples affected with 

 scab began rotting while still attached to the trees, the loss in some cases amount- 

 ing to four-fifths of the entire crop. 



Fig. 2. — "Scab" spots on an apple. (Original.) 



Among the fungi which produces soft rot of apples and which usually attack 

 the fruit where scab exists, the following have been noted as most common in 

 this state: 



Cephalothecium roseum. 

 Penicillium glaucum. 

 Sclerotinia fructigena. 

 Mucor stolonifer. 



PREVKXTION AND TREATMENT. 



The fungus of apple scab thrives during moist cool weather, consequently the 

 disease is apt to be most prevalent during seasons when such weather prevails 

 especially during the early part of summer. Fruit grown on closely crowded 

 trees where air and light are shut out appears to be more severely affected than 

 where the opposite conditions prevail. Therefore a location securing good ven- 

 tilation, proper spacing of trees, and systematic pruning are to be considered 

 as preventive measures in the case of this disease. It has been found that the 

 fungus passes the winter on the fallen leaves, appearing as minute, black bodies 

 buried in the leaf tissues. From these are given off in the following spring the 

 first crop of spores which attack the lower leaves, the disease later spreading 

 to all parts of the tree. Thus another prventive measure is suggested and 

 recommended, viz.: the destroying of these dead leaves which serve as agents of 

 infection. This may be done either by raking and burning them or by plowing 

 them under in spring before the spores are shed. 



