192 



Mycologia 



plant pathology. For this purpose reprints, pamphlets, and bul- 

 letins are more suitable than bound volumes of periodical publi- 

 cations, and as these are often not available for purchase, Mr. 

 Butler would be grateful to authors who have pamphlets or re- 

 prints to spare, if they would present one or two copies so that 

 their work may be readily brought to the notice of isolated work- 

 ers in the outlying parts of the British Empire. 



A very beautifully illustrated paper by F. R. Jones and C. 

 Drechsler on crown-wart of alfalfa, caused by Urophlyctis Al- 

 falfae, appeared in the Journal of Agricultural Research for No- 

 vember 15, 1920. This disease has been found to have its origin 

 in the infection of very young buds, the foliar elements of which 

 develop into abnormalities not involving the mature structures of 

 root or stem. Infection appears to take place only early in the 

 spring, becoming easily discoverable in the latter part of March 

 or in early April in northern California. The abundant develop- 

 ment of the disease in the regions where it now occurs is appar- 

 ently associated with excessive moisture during the period when 

 infection is taking place. Any measures which can be taken to 

 reduce the moisture near the surface of the soil at this time should 

 reduce the disease. 



Fusarium oxysporum nicotianae is the name proposed by John- 

 son in the Journal of Agricultural Research for January 3, 192 1, 

 for a wilt disease of tobacco found in Maryland and Ohio. The 

 conditions favoring infection with the tobacco-wilt organism are 

 heavy soil infestation, wounded host tissue, a relatively high soil 

 temperature (28 0 to 31 0 C), and a susceptible variety. The 

 White Burley is most susceptible, and the Havana Seed and 

 Cuban varities are among the most resistant. Where the disease 

 threatens to become serious, growers are advised not to grow 

 tobacco on the infested soils and to avoid the danger of infested 

 seed beds. The most hopeful means of control appears to lie in 

 the development of strains resistant to the disease within the 

 various susceptible varieties. 



