DISEASES OF PLANTS. 761 



the root showed no external symptoms of disease Ijeyond l)eing drier and tougher 

 than normal. When c-ut across, the vascular bundles were stained with a purplish- 

 black ttolor. Specimens removed from the field and grown in the greenhouse 

 showed that while the disease did not actually kill the plants it greatly stunted 

 their growth. Examination of the vascular bundles showed that they were filled 

 with a mucilaginous mass containing large numbers of bacteria. The symptoms 

 presented by this disease seemed to be identical with a disease reported on sugar 

 beets, and it is believed to be due to the same cause. 



Bacterial disease of the potato, G. BATTAXcnox (Prog. Ayr. et Vit. (Ed. IJEs^t), 

 2J {1901), Xo. 37, pp. 318-3:^1). — An account is given of the occurrence in a number 

 of localities in France of the bacterial disease of potatoes believed to be identical 

 with that described by Erwin F. Smith as due to Bacillus solanacearum (E. S. R., 8, 

 p. 895). The characteristics of the attack are described at some length and a number 

 of instances cited to show the extent of injury caused by the attack. 



A bacterial disease of tomatoes, W. Stuart {Proc. Indiana Acad. Sd., 1900, pp. 

 153-157, figs. 2). — This is an abstract of an article published in the Thirteenth 

 Annual Report of the Indiana Station (E. S. R., 13, p. 57). 



A report on the condition of vineyards in portions of the Santa Clara Val- 

 ley, F. T. BioLETTiand E. H. Twight {California Sta. Bid. 134, ])p. ll,fig-'i- 4).— An 

 investigation was carried on to determine the cause of the failui'e and death of a large 

 number of vines in certain parts of California during the past 3 years. The dying of 

 the vines was most conspicuous in the Santa Clara Valley, but similar cases were 

 reported from other regions. In the Santa Clara Valley nearly all the older vine- 

 yards were more or less affected, in some cases nearly every vine being destroyed; in 

 others the injury was sporadic. The distribution of the injured and dead vines was 

 such as to suggest that the disease was not of an infectious i^arasitic nature. Dead vines 

 were found to have been severely injured, usually by the cutting off of large branches 

 at pruning, and leaving large wounds. These did not heal over and a decay set in, 

 resulting in some cases in the hollowing out of the interior of the vine. This decay 

 furnished a suitable locality for boring insects and the growth of wood-rot fungi. It 

 was noted that in nearly every case the dying vines were old, although there was a 

 great difference in the behavior of different varieties. The death of the vines, as 

 shown by the investigation, seems to be due to a number of causes which may be 

 more or less supplementary. Among them are mentioned growing on excessively 

 gravelly soil, susceptibility of certain varieties due probably to heavy bearing, large 

 wounds made in pruning, age of the vine, and the injurious effect on the young 

 growth by spring frosts. These causes acting independently or in combination, 

 together with the combined effect of the heavy crops of 1896 and 1897, and the 4 years 

 of drought which followed, are believed to be the reason for the destruction. It has 

 V>een suggested that the death of the vines was due to what is known as the California 

 vine "lisease, but the destruction in this case bears no resemblance to that disease. 



Powdery mildew on grapes, J. M. Guillon and G. Gouirand {Rev. Vit., 16 

 {1901), No. 404, PP- 293-295). — The authors report the abundant occurrence of the 

 perithecial stage of UDcinula spiralis upon grapes in a number of localities in France. 

 The powdery mildew in Euroi)e does not ordinarily produce the perithecia, but 

 the climatic conditions seem to have l)een favorable to an abundant production dur- 

 ing the season. 



Combating- grape mildew by early pruning, L. Plagnes {Prog. Agr. et Vit. 

 {Ed. Jj'Est), 22 i 1901), Xo. 44, p. 510). — It is claimed that pruning grapevines in 

 Octol>er, following this treatment with 2 applications of sulphur in the early spring, 

 is of decided a<lvantage in combating the grape oidium. Experiments are cited in 

 which comparisons were made l>etween vines pruned in October and others in Feb- 

 ruary or March, both of which received the same sulphur treatment. The result of 

 this experiment was decidedly in favor of the early pruning. 



