ABSTRACTS 133 



tacks both the lodgepole pine and the yellow pine increases the diffi- 

 culty of control of this fungus. — S. H. A. 



Sweet Potato Scurf. L. L. Harter. Jour, Agr. Res., 1916, 5, 787-793. 

 The scurf disease of the sweet potato was first recognized in 1890 

 by Halsted, who named the fungus " Monilochaetes infuscans," a 

 new genus and species. He failed, however, to describe either the 

 genus or species. The scurf has been found prevalent in nine States 

 and sparingly in others, and on 16 varieties of sweet potatoes. The 

 organism has been shown by inoculation experiments to be the true 

 cause of the disease. A detailed discussion of the morphology of the 

 organism is taken up, also its growth on different culture media at 

 different temperatures. It was found that the organism on the host 

 consisted merely of sporophores and conidia. In the culture, however, 

 well-defined branched mycelia and spores developed. — S. H. A. 



Further Studies on Peanut Leaf spot. Frederick A. Wolf. Jour. 



Agr. Res., 1916, 5, 891-902. 



A continuation of work on the fungus diseases of peanuts, the ob- 

 ject being to secure information regarding the agencies concerned in 

 the distribution of leafspot, Cercospora personata (B. and C.) Ellis, 

 and to correlate the destructiveness of the disease with the presence of 

 certain climatic conditions. Crop rotation was not found effective 

 under field conditions in eliminating leafspot; nor was the disease 

 prevented by seed disinfection with copper sulphate or formaldehyde 

 before planting. No correlations between the presence of certain con- 

 ditions of temperature and moisture and the presence of leafspot 

 exist because of the fact that air currents and certain insects are carriers 

 of Cercospora personata. — S. H. A. 



Soil Stain, or Scurf of the Sweet Potato. L. J. Taubenhaus. Jour. 



Agr. Res., 1916, 5, 995-1001. 



The economic importance of the disease is discussed, also the occur- 

 rence of soil stain, symptoms of soil stain, effect of the disease on the 

 host, factors favorable to soil stain development, the cause of soil 

 stain or scurf and the morphology and physiology of the fungus caus- 

 ing the scurf. The fungus Monilochaetes infuscans was found to be 

 difficult to culture because it is a very slow grower and is readily over- 

 run by associated saprophytes. The conidiophores of M. infuscans 

 are distinct from the mycehum, the older growth of which is also dark. 

 The conidia are borne in chains which readily break up when moistened 

 or disturbed. — S. H. A, 



Factors Involved in the Growth and the Pycnidium Formation of Pleno- 

 domus fuscomaculans. George Herbert Coons. Jour. Agr. Res. 

 1916, 5, 713-770. 

 This paper gives the result of experiments performed with Pleno- 



domus fuscomaculans, a fungus pathogenic to the apple. The organ- 



