230 MANUAL OF FRUIT DISEASES 



the attacks of the black-rot and downy-mildew pathogenes 

 than when besieged with powdery-mildew and anthracnose fungi. 

 From these facts it is clear that the pedigree of a variety is an 

 essential indication of the probable susceptibility to disease. 



BLACK-ROT 



Caused by Guignardia Bidwellii (Ellis) Viala ahd Ravaz 



The first important records of black-rot come from Missouri 

 in 1861, although the disease had been known many years 

 prior to this date. About that time (1861) there was a rise in 

 the grape industry near St. Louis, which, especially in 1860 

 to 1864, was accompanied by epiphytotics of black-rot. In 1885 

 the disease was first recognized in France, into which country 

 the pathogene had, at some previous date, been introduced 

 from America. In 1886 there was very little of the disease, 

 owing to the dry weather ; however, in 1887 it became serious in 

 many localities new to the trouble. The vineyardists abroad 

 were desirous of obtaining the best varieties and so they went 

 not only to the wild grapes for cuttings, but imported them 

 from America. They were further interested in getting posses- 

 sion of varieties resistant to the phylloxera, and consequently 

 the introduction of the black-rot organism was comparatively 

 easy. So serious had the grape-disease situation become in 

 France by 1887, that the noted Viala was detailed by the French 

 government to visit America in the interest of French viti- 

 culture. Since this date many papers dealing with the disease 

 have appeared in various languages, but more particularly in 

 French and English. 



At present the black-rot disease is practically omnipresent. 

 Its geographical range in Europe is approximately coincident 

 with that of the grape; for the pathogene, having reached 

 France, spread rapidly into Germany, Italy and Asia Minor. 



