181) 



MYCOLOGICAL STUDIES. I 



ON THE "SPOTTING" OF APPLES 

 IN GREAT BRITAIN 



By ARTHUR S. HORNE 



AND 



ELEANOR VIOLET HORNE. 



{From the Department of Plant Physiology and Pathology, 

 Imperial College of Science and Technology.) 



(With 6 Text-figures.) 

 CONTENTS 



PAGE 



1. Introduction 183 



2. Symptoms . . . . . . . .185 



3. The fungi concerned 189 



4. Special relations of the fungi concerned in "spotting" 191 



5. Inoculation experiments with Pleospora pomorum . 193 



6. Control 199 



7. Summary 201 



1. Introduction. 



This investigation was undertaken with a view to enquiring into the 

 nature and origin of the spots which occur on the surface of a large 

 number of varieties of apple, including many much prized for culinary 

 and dessert purposes in this country ; these spots, which begin to appear 

 towards the end of the summer, spoil the appearance of the apple and 

 are often the cause of premature decay. 



This "spotting" of apples is prevalent in the United States and in- 

 vestigations have been undertaken or are in progress at several of the 

 Agricultural Experimental Stations there. The earlier workers, notably 

 L. R. Jones (Vermont) 1 , Longyear (Michigan) 2 and Lamson (New 

 Hampshire) 3 , attributed the "spotting" to various fungi, for example, 



1 Jones, L. R. Vt. Agr. Exp. Sta. Bept. 5 (1891), p. 133. 



2 Longyear, B. 0. Spec. Bull. Mich. Agr. Expt. Sta. 25 (March, 1904). 



3 Lamson, W. H. N. H. Coll. Bulls. Nos. 27 (Apr. 1895), 45 (May, 1897), 65 (May, 1899), 

 101 (Apr. 1903). 



