DISEASES OF PLANTS. 847 



the other varieties tested, only Theunissen, a strain of Rietti, and Thew 

 promise to be valuable. 



Of the 4 varieties of oats tested, all proved rust resistant during 1908 and 

 1909, while the variety called Texas was especially valuable on account of its 

 good hay and heavy yield of grain. 



Some observations on bunt and fungicides, G. P. Darnell-Smith {Agr. Gas. 

 N. 8. Wales, 21 {1910), No. 9, pp. 151-156, pi. 1, figs. S).— A report is made on 

 a series of observations on bunt of wheat {Tilletia triiici and T. levis) con- 

 ducted at the Milson Island Experiment Station, in which the point of infec- 

 tion on the grain, resistance of certain varieties of wheat to smut, and the 

 effects of certain fungicides on the germination of the grain, were tested. 



It is claimed that in artificially infected grain, the bunt spores adhere chiefly 

 to the brush or tuft of hairs on the end of the grain opposite to the embryo, 

 which situation affords ideal conditions for their development by reason of the 

 air entangled in the tuft of hairs. The seed coat, being weakest at that end, 

 bursts there first during germination, thereby permitting the easy access of 

 the smut hyphse into the interior of the grain. 



Three varieties of wheat proved immune to both species of bunt, even when 

 the seed planted were previously dusted with bunt spores, while non-resistant 

 varieties treated in the same manner produced smutty heads. 



In the tests with fungicides, formalin, copper sulphate and lime, and copper 

 sulphate alone being used, it was found that the 2 per cent solution of copper 

 sulphate injured seriously the germination of the seed. Subsequent treatment 

 with lime prevented this deleterious effect. 



A new disease of alfalfa, G. Arnaud (Prog. Agr. et Vit. {Ed. VEst-Centre), 

 31 {1910), No. J/S, pp. 511-519, fig. 1). — Attention is called to the appearance 

 on alfalfa in France of this well known wilt of cotton, cowpeas, etc. The causal 

 organism, Neocosmospora vasinfecta (E. S. R., 11, p. 944), is figured and de- 

 scribed. The selection of resistant varieties, crop rotation, and the disinfection 

 of the soil with carbon bisulphid and formalin are suggested as remedies. 



Cotton diseases in Mississippi, R. P. Hibbard {Mississippi 8ta. Bui. U/O, 

 pp. 21, figs. 8). — This contains a popular discussion of cotton diseases in general 

 and of the symptoms, cause, and remedies of the following specific diseases : 

 Cotton wilt {Neocosvwspora vasinfecta), anthracnose {CoUetotrichum gossypii), 

 cotton rust (physiological), red rust {Tctranychns tclarius), sore shin {Rhizoc- 

 tonia sp.), bacterial blight {Bacterium malvacearum) , shedding of bolls (physi- 

 ological), root galls {Heterodera radicicola), root rot {Ozonium omnii^orum), 

 areolate mildew {Ramularia areola), and cotton leaf blight {Cercospora gossy- 

 pina). A bibliography of cotton diseases is appended 



Cotton diseases in Mississippi, R. P. Hibbard (Mississippi 8ta. Bui. V/O-B, 

 pp. 16, figs. 8). — A i-epriut of those portions of the above bulletin which deal 

 with the specific diseases of cotton. 



On the leaf roll and other diseases of the potato, K. Stormer {Illus. Laiidw. 

 Ztg., SO {1910), No. 11, pp. 661, 668).— In a discussion of the causes of leaf 

 roll and late blight of the potato, the author claims that if the weather condi- 

 tions during the fall are favorable to a thorough ripening of the tubers and 

 such tubers are used for seed the following spring there will be no epidemic of 

 leaf roll or Phytophthora that year. 



Varieties of potatoes resistant to wart disease {Jour. Bd. Agr. [London], 

 11 {1910), No. 1, pp. 556-558). — The results are given of a series of experiments 

 conducted in 1909 and 1910 on the resistance of various varieties of potatoes to 

 the wart disease. 



The potatoes were planted in soil thoroughly infected with the spores of the 

 fungus. For 1909, 5 varieties were found resistant, though of these only 2 



