DISEASES OF SPECIAL CROPS 77 



ing. One county alone is 

 estimated to have suffered a 

 loss of $950,000. Owing to 

 its superficial similarity to the 

 scab, it has perhaps been 

 confounded with it in some 

 instances. The first publica- 

 tion concerning the disease 

 appeared in 1902,' and the first 

 detailed description in 1907.- 

 Upon the fruit the blotches 

 are from 5-10 mm. in diam- 

 eter, dark in color, with an 

 advancing margin of very 

 peculiar, irregular, jagged, or 

 fringed appearance. By co- 

 alescence large spots may 

 form, and owing to tension, 

 cracks appear, enlarging to a 

 centimeter in length, or even 

 girdling the fruit, and reach- 

 ing to the core. In the older 

 portions of the blotch, minute 

 pycnidia develop. These 

 blotches mar the appearance 

 of the fruit and injure it as fiq. 27.— Apple blotch (phyiiostictose) 



, , , T . on twigs. Original. 



a salable product. 

 Upon twigs, spurs, or shoots are produced cankers, 



> Clinton, G. P., III. Agr. Exp. Sta. Bui. .69, pp. 190-192. 

 ' Scott, W. M., and Qualntance, A. L., U.S. Dept. Agr. Farmers' Bui. 

 283, pp. 14-18. 



