260 MANUAL OF FRUIT DISEASES 



Gregory, C. T. A rot of grapes caused by Cryptosporella viticola. 



Phytopath. 3 : 20-23. 1913. 

 Selby, A. D., and Van Hook, J. M. Dying of bearing grape-vines. 



Ohio Agr. Exp. Sta. Circ. 64 : 1-6. 1907. 

 Shear, C. L. The ascogenous form of the fungus causing dead-arm 



of the grape. Phytopath. 1 : 116-119. 1911. 



WHITE-ROT 



Caused by Coniothyrium diplodiella (Speg.) Sacc. 



It is probable that the pathogene causing white-rot is native to 

 America, although it was first found in Italy about 1878. In 

 1885 it was observed in France, and in 1887 considerable alarm 

 was aroused because of white-rot. That same year the disease 

 was first noted in America, having been found in southwestern 

 Missouri and neighboring territory. Since its discovery in the 

 United States the disease has appeared in Ohio and New York 

 and the grape-growing regions of the Southwest. In recent 

 years white-rot has been found in Algeria and Hungary. 



White-rot is regarded as one of the less important of the 

 grape diseases in America. It is not often serious, although it 

 is said to do damage in some parts of Ohio. The amount of 

 losses from white-rot is decidedly greater in European vine- 

 yards than in those of this country. 



Symptoms. 



White-rot affects the fruit, young shoots, stems of berries, 

 and rarely the foliage. 



Berries may or may not be directly affected. Generally the 

 disease appears first on the fruit-stalks, as a result of which the 

 berries wither and become dry. Berries affected directly show 

 brown-rot lesions. The fruit becomes abnormally juicy, shrivels, 

 and brownish pustules appear over the surface. Berries may 

 be affected after maturity. In severe cases all fruits in a single 

 bunch may be diseased. Eventually a dry mummy is produced, 



