APPLE DISEASES 



475 



of the sunounding ones. The crown and 

 large roots of these trees had been left 

 exposed for two seasons with no apparent 

 ill effect, the earth being thrown back 

 over them, however, each winter. A trial 

 of these methods is recommended. It may 

 be that simple root exposure would help 

 to check the disease or that thorough 

 cutting out and sterilization would stop 

 its progress, but so little experimentation 

 has been done along these lines that def- 

 inite assurances of success cannot be 

 made. 



Biblioprapby 



1910. Washington Experiment Station, 

 Bulletin No. 3. Special Series. 



1911. Pennsylvania Experiment Station, 

 Bulletin No. 152. 



1911. Arkansas Experiment Station, Bul- 

 letin No. 71. 



1911. Ohio Experiment Station. Bulletin 

 No. 214. 



1912. Oregon Experiment Station, Crop 

 Pest Report, 1911-12. 



California Com. Hort., II No. 6. 

 California Fruit Growers' Report. 1910, 



Page 93. 

 1901. Oklahoma Experiment Station, 



Bulletin No. 49. 

 1903. Washington Experiment Station, 



Bulletin No. 59. 



A >'ew Disease on Apples 



A new disease on apples has been re- 

 ported by the Pennsylvania State College* 

 and described as follows: 



"This disease is apparently physiolog- 

 ical, and appears most conspicuously as 

 an affection of the twigs of the current 

 season's growth, though it is not confined 

 to them. The twigs lose their normal 

 color and become dull and of a rather 

 blistered and mottled appearance at first. 

 At a casual glance the effect somewhat re- 

 sembles that produced by an incrustation 

 of the San Jose scale. Immediately under 

 the epidermis of the diseased areas and 

 extending about half way to the cambium, 

 in the early stages, there are numerous 

 small, brown spots or pits where the tis- 

 sues are dead or dying. Later, on the 

 surface, the epidermis usually cracks 



♦Pennsylvania State College Report, 1910-11. 



around and over the diseased spots and 

 they become rough, dark, and rather scab- 

 like, and are usually slightly sunken 

 through the drying out and death of the 

 tissues underneath. In some cases the 

 cracks may go deeper and involve the 

 wood. The leaves are also affected sooner 

 or later, probably through the girdling of 

 the twigs below them. They turn brown, 

 dry out and crumble, beginning at their 

 tips and outer margins. In time, the 

 twig, limb or whole tree may be killed. 



"The disease usually becomes well de- 

 veloped and conspicuous by the middle or 

 latter part of August." 



No remedy is suggested but the indica- 

 tions point to fertilizer trouble. 



>'ew Hampshire Fruit Spot 



See Cylinclrosporium Fruit Spot. 



?few York Apple Tree Canker 



See BJack Rot. 



Orange Rust 



See Coryneum Leaf Spot. 

 Penecillium. See Blue Mould. 



Fink Rot 



Cephalothecium roseum 



This fungus has been found to accom- 

 pany scab and seems to gain entrance to 

 the apple at points of rupture in the skin 

 caused by the scab. It is called "pink 

 rot" on account of the color of the spots 

 as the fungus matures. Its first appear- 

 ance, however, is that of a thin gray film 

 of mildew. 



It develops both in and out of storage. 

 The rot has been very destructive at times 

 in New York. The method of control is 

 the same as for scab, which see. 



References 



1902. Cornell Bulletin No. 207. 



1903. New York Bulletin No. 235. 

 Pome Blight. See Blight under Pear. 



Powdery Mildew 



Sphaerotheca mali 

 H. S. Jackson 

 The apple powdery mildew is a com- 

 mon disease in nearly all fruit sections of 

 the Northwest. 



This disease was formerly considered 

 as most serious on nursery stock, but un- 



