DISEASES OF PLANTS. 1085 



Potato scab experiments were carried on during the seasons covered by the report 

 in wliich the susceptibility of different varieties was tested. In 1901 11 varieties 

 were tested and in 1902 14 varieties. A comparison of the results shows considerable 

 difference in the behavior of the different varieties, and the results are such as to 

 lead to the hope tliat scab-resistant varieties maj^ be secured by breeding and selec- 

 tion. Disinfection experiments in whi(;h formalin, corrosive sublimate, and formal- 

 dehyde vapor were tested for scab prevention were carried on and, as in all previous 

 trials, both corrosive sublimate and formalin solutions proved equally efficient. The 

 experiments with sulphur fumes and formalin vapor are to be continued. 



Diseases of the potato in Ireland, T. Johnson {Jour. Dept. Agr. and Tech. 

 Instr. Ireland, 3 {1003), Nv. 1, pp. 8-21). — Attention is called to a number of diseases 

 of potatoes which occur more or less abundantly in parts of Ireland, at times causing 

 serious losses. The potato blight {PerunoKjxira InfeManH) and the sclerotium disease 

 {Srierot'mia scleral ioriDn), as well as the bacterial and Ehizoctonia diseases of potato 

 are described, and an account given of the attack of Phellom>/ces aclerotlophorns upon 

 the potato. So far as the author is aware this fungus has not previously been 

 observed in Great Britain, and while truly parasitic may cause considerable unsus- 

 pected damage to the potato crop. It gives rise to a skin disease or scab of the potato 

 tuber, followed by the rotting of the potato. In the earlier stage the presence of 

 the fungus is indicated by the appearance of white shining patches on the skin of the 

 tubers, and later the ei^ideimal layers peel off leaving the underlying tissues exposed 

 to the rot fungi. The disease may be carried over from one crop to another by plant- 

 ing with infected tubers and care should be taken to exclude them when ol)served. 



Notes are given on a number of diseases of other plants, most of which are of com- 

 mon occurrence. 



Some diseases of the potato and of fruit trees, A. Linton {Jour. Kliedir. Agr. 

 Soc. and School Agr., 4 {1903), No. 5, pp. 197-208, ph. 4)- — A description is given of 

 a number of diseases of the potato and of various fruit trees that are caused by 

 attacks of fungi, insects, or other animals. Among the diseases of the potato the 

 most loss is occasioned by attacks of the early blight {Macrosporium solani). The 

 early planting of potatoes, the use of less susceptible varieties, and spraying with 

 Bordeaux mixture are recommended as preventive measures. The enemies of the 

 fruit trees described are mostly insects, stem borers and scale insects predominating, 

 with notes on peach-leaf curl, ]>lum rust, grape downy mildew, etc. 



A new fungus disease of potatoes, K. S. MacDougall ( Trans. Iligldand and 

 Agr. Soc. Scotland, 5. ser., 15 {1903), ])]>. 312-319, figs. 4). — A description is given of 

 a disease of potatoes caused by the fungus Chrysophlyctis endoJiiotica. This disease 

 has been previously described (E. S. R., 14, p. 979), and attributed to attacks of 

 this fungus as well as to CEdomyces leproides. The life history of the fungus is 

 described, and its occurrence on the potato crop is said to have first been noticed in 

 1899. In 1900 it was less al)undant, but in the following years was quite prevalent. 

 It is characterized by a peculiar warty outgrowth in the tubers, and commences 

 about July or August, developing with the potatoes. Infection is usually through 

 the eyes of the tubers, and may result in warty excrescences that are sometimes 

 even larger than the potato itself. The disease is likely to manifest itself most seri- 

 ously in damp places, although no percei^tible deficiency has been noticed in the 

 crop. After the potatoes are dug there appears to be no further development of the 

 disease, nor do the affected potatoes seem more liable to decay. In planting the 

 seed tubers should be carefully examined, and all affected ones rejected. 



A bacterial disease of sugar beets, G. Cr. Hedgcock and H. Metcalf {Ztschr. 

 Fflanzenhrank., 12 [1902), No. 6, pp. 321-324)- — A description is given of a disease of 

 sugar beets wliich was recognized In' the authors in various parts of Nebraska during 

 the autumn of 1901 and later reported to them as occurring in Arizona and Colorado. 

 As a result of the attacks of the bacteria the roots begin rotting at their tips and later 

 the leaves and all the above-grouml parts of the beets become entirely infested. The 



