DISEASES OF PLANTS. 543 



Experiments for the control of the disease indicated that spraying with 

 Bordeaux mixture would keep it in check. 



Further observations on Phytophthora erythroseptica and on the disease 

 produced by it in the potato plant, G. H. Pethybridge ( Sci. Proc. Roy. Dublin 

 /S'oc, n. sen, U {19U), No. 10, pp. 179-198, pi. 1, figs. 2).— This paper contains 

 further observations on P. cri/throseptica which has been previously shown to 

 he the cause of a pink rot of the potato (E. S. R., 29, p. 550). 



The author states that the reproductive organs of the fungus have been 

 found in all of the underground parts of the plant, including in one case a 

 luber. Plants affected with this fungus exhibit symptoms of disease in their 

 subaerial organs which are of the wilt type. On account of this character he 

 suggests that the disease be known as pink i*ot wilt. The disease is considered 

 contracted from the soil and is of serious consequence only in land which has 

 been continuously in potatoes for several seasons. 



Potato leaf roll, L. von Beke (Jahresber. Ver. Angew. Bot., 10 {1912), pp. 

 145-155). — In a brief preliminary report of studies on potato leaf roll the 

 author states that the disorder is thought to be hereditary and infectious. 

 The trouble does not seem usually to spread from a center. Three different 

 forms or degrees of development are described. Field experiments continued 

 for three years in different jiarts of Hungary on infected and uninfected soils 

 showed the hereditary character of the disorder and the increase of intensity 

 in case of infected seed tubers when planted on infected soil, plants grown 

 from healthy seed on noninfected soil showing no trace of the trouble. Differ- 

 ences in violence of the attack appeared more closely related usually to 

 weather, soil. etc.. than to variety used, although two varieties used were 

 severely attacked. The influence of soils, elevation, climate, culture, and I'ota- 

 tion are briefly discussed. 



In laboratory studies mycelium of each of four fungi, Fiisarium solani, F. 

 discolor, F. gibhosum, and F. subulaUim was used, the infection being accom- 

 plished by spraying or dipping on April 29. Disease symptoms appeared late 

 in August and on September 5 only 14 out of 120 plants tested were free from 

 symptoms resembling those of leaf roll. 



Decisive results have not yet been obtained from field tests in which the 

 plants were sprayed with liquid containing spores, spraying with mycelium 

 appeai'ing to cause infection more readily. 



Microscopic investigation of the tissue failed to show invariable correspond- 

 ence between the disease and the presence of mycelium. The latter was more 

 frequently noted in the lower third of the aerial portion and in the roots near 

 the surface. It was found only once in the vascular bundles of the leaves, 

 but commonly in the vascular bundles of the tubers near their point of attach- 

 ment. Young sprouts from diseased tubers showed no mycelium. 



The potato diseases of Michig'an, G. H. Coons {Michigan Sta. Spec. Bui. 

 66 {1914), pp. 31, figs. 13). — Popular descriptions are given of the late blight, 

 early blight, scab. Rhizoctonia, dry rot. wet rot, deep scab, and Fusarium wilt, 

 all of which are reported as being present in Michigan, and in addition brief 

 accounts are given by E. A. Bessey of the wart disease, curly dwarf disease, 

 leaf roll, blackleg, and powdery scab, none of which have yet been reported 

 as occurring in that State. In connection with the different diseases control 

 measures are discussed at length. 



Diseases of sugar beets, O. Fallada {Osterr. TJngar. Ztschr. Zuckerindus. u. 

 Landw., 43 {1914), No. 1, pp. 23-28, fig. i).— This is part of the 1913 report by 

 the author on the enemies and diseases of sugar beets, and includes brief gen- 

 eral notes on root rot, heart and dry rot, and scab, and also on some diseases 

 affecting the leaves. 



