Pflanzenkrankheiten. 281 



and ascospores. their description and their significance in spreading 

 the disease. M. J. Sirks (Haarlem). 



Reuther. Beobachtungen über die Fussk rankheit des 

 Weizens. (111. landw. Zeit. N« 65. p. 589—591. 1913.) 



Eigene Beobachtungen des Verf. führen zur Aufstellung folgender 

 Erreger bezw. Förderer der genannten Krankheit: Einige Arten 

 der Gattung Fusarimn, Leptosphaeria cuhnifraga mit den Halm- 

 tötern Ophiobolns gvaminis und O. herpotrichoides (gemeinsam in 

 fusskranken Böden vorkommend), zu grosse Nässe und zu dichter 

 Stand, ungünstige Ernährung und Untergrundverhältnisse, Einfluss 

 der Fruchtfolge, V^erunkrautung, Frühjahrsfröste. Es werden 10 

 Bekämpfungsgesetze aufgestellt, aus denen auch erhellt, dass als 

 Beizmittel Sublimoform das Formaldehyd ersetzen kann. 



Matouschek (Wien). 



Stakman, E. C. and R. C. Rose. A fruit spot of the wealthy 

 apple. (Phytopathology. IV. p. 333—335. 1914.) 



The Wealthy apple is most frequently affected by a disease, 

 called the Wealthy disease by Minnesota growers, but it is b}^ 

 no means confined to this variety. The opinion of the growers is 

 that the thin skinned varieties are most frequently and serioush' 

 affected. The disease is characterised by the appearance of spots. 

 brown or black, usually quite distinctly sunken, with very Sharp 

 borders and often around a lenticel, superficial, the dry brown 

 tissue seldom being more than one or two millimeters deep. The 

 spots are very similar to the socalled Jonathanspots on Jonathan 

 apples, but these are not grown in Minnesota. The authors 

 isolated many fungi from the diseased tissues, but AUevnaria sp. 

 wa^ the only, which developed with considerable consistency. The 

 checks produced no Alternavia. Inoculations were made without 

 injuring the apples, but these gave no results. Only when needle 

 punctures were made, typical spots, in no way distinguishable 

 from those naturally occurring on apples, developed Rfter Alternaria- 

 inoculation. M. J. Sirks (Haarlem). 



Taubenhaus, J. J., Recent studies of some new or little 

 known diseases of the sweet potato. (Phytopathology. IV. 

 p. 305-320. 1914.) 



The typical charcoal rot, a disease of considerable economic 

 importance, is obtained when Sclerotium bataticola Taub, is the only 

 invader. When the fungus is followed by Fusarium hatatatis WoU , 

 the affected root does not turn charcoal, but takes on an ashen 

 color which varies with the predominating fungus. Infection seems 

 to take place at a bruise on the epidermis and from there the fun- 

 gus works slowly inwards. 



Soft rot, caused b}" Rhisopus nigricans Ehr. is the subject of 

 the following part of this paper. The history of our knowledge 

 about it, its occurrence and syptoms, its pathogenicity with experi- 

 ments, made b}^ the author about the influenae of moisture (open 

 versus closed moist Chambers, the resistance ofsomeroots, although 

 exposed to ideal conditions for infection, the fruiting conditions of 

 the causing fungus, the odor of soft rot emitted by diseased pota- 

 toes by acetic fermentation after a week or ten days and attracting 



