84 PROTECTION OF PLANTS — 1924-25 



Conclusions. 



The immature teliospores of Puccinia Malvacearum are able to withstand 

 the severity of winter in Quebec and germinate the next spring producing infec- 

 tion of healthy plants. 



The percentage of teliospores which overwinter and the percent viable is 

 very low so that the teliospores cannot be considered as the chief means of 

 spring infection in Quebec. 



Bibliography. 



Taubenhaus, J. J. A contribution to our knowledge of the morphology 

 and life history of Puccina malvacearum Mont. • — Phytopathology 

 1:55-62. —Pi. XII— XIV, 1911. 



ABSTRACTS OF CANADIAN PLANT PATHOLOGICAL LITERATURE. 



A. W. McCallum. 



The abstracts and references given herewith include the papers on plant 

 pathology pubhshed in Canada during 1924. 



Bariheau, B. Fletrissure et Pourriture de la Tige du Tournesol dans la 

 Province de Quebec. Sci. Agric. 3:397—400. Fig. 1-6. 1923. — The 

 symptoms of the wilt of sunflowers which has been noted in several districts in 

 Quebec are described. Beans and turnips were also found affected. The 

 sclerotia overwinter in the soil and remain viable for at least two years. The 

 causal fungus is believed to be Sderotinia libertiana. 



Bishy, G. R. The Sderotinia Disease of Sunflowers and other plants. 

 Sci. Agric. 4: 381-384. PI. 1. 1924.— In Manitoba sunfloWets, and carrots and 

 parsnips in storage are subject to severe injury by Sderotinia. Alfalfa, red 

 clover, soy bean, and sow thistle are also attacked. Sclerotia from sunflowers 

 were germinated and the measurements of the asci and ascospores were found to 

 agree with those of Sderotinia sderotiorum. From the fusions of hyj hse in cul- 

 ture from different hosts and from cross-inoculations it was concluded that but 

 one fungus was present and that was S. sderotiorum. 



Brittain, W. H. Methods employed in recording results of spraying and 

 dusting experiments in apple orchards. Sci. Agric. 4: 141—151. 1924. 



Dickson, B. T. Saltation in the Organism causing "Black Dot" Disease of 

 Potato in Canada. Trans. Roy. Soc. Can. (3rd series). 17 (Sect. 5): 123-128. 

 PI. 3. 1923.' — In culturing the organism which causes black dot of potatoes 

 two variants of the type form, one which produced conidia only and one which 



