546 EXPERIMENT STATION EECORD. 



ings after hard winters are more in clanger than early ones. Turning under 

 the surface mold to a depth of 30 cm. reduces considerably the number of plants 

 attacked. Drill cultivation did not tend to reduce the attaclis, but the plants 

 individually withstood the attaciis better. Rotation proved ineffective, as a 

 number of the crops most grown in that region are attacked by the nematode. 

 These include, besides rye of both winter and summer varieties, oats and buck- 

 wheat. Barley, clOA-er, and other plants suffer but little, if at all. 



Control of loose smut of wheat (Ustilago tritici) and of barley (U. nuda), 

 O. Appel and E. Riehm {Arb. K. Biol. Anst. Land u. Forstiv., 8 (1911), Xo. 3, 

 pp. 3Jf3--'t26, pi. 1, figs. 2). — Continuing their communications under this head 

 (E. S. R., 25, p. 453) the authors submit a rather elaborate report, giving a 

 brief history of investigations on these destructive fungi and on means and 

 methods employed for their control. Special attention is given to the applica- 

 tion of heat to the seed grain through the medium of air and water. Various 

 forms of apparatus tested are discussed and recommendations given as to Ivinds 

 preferred and also as to temperatures to be employed and their duration; these 

 are (in the principal treatment) for water a temperature of 50 to 52° C. 

 maintained for from 7 to 10 minutes, and for air 50° for 5 minutes only. 



Cabbag-e disease in Lang'endijk, J. Ritzema Bos and H. M. Quanjee 

 (Tijdschr. Plantenziekten, 16 (1911), No. Jf-6, pp. 101-11(8, figs. 2).— The 

 authors give the results of a 10 years' study of local diseases affecting varieties 

 of Brassica oleraeea and of means for their control. The diseases in ques- 

 tion include those due to bacteria and fungi, among which are mentioned 

 Pseudomonas campestris (black rot) and Phoma oleraeea; those due to insects; 

 and those due to unfavorable soil conditions. Safeguards and remedies are 

 discussed in some detail and recommendations made as to means and methods 

 of application. 



The brunissure of cotton in Algeria, A. Maige and G. Nicolas (Bui. Soc. 

 Hist. Nat. Afrique Nord, 2 (1910), No. 4, pp. 65-68).— The authors describe a 

 disease of cotton to which the name brunissure is given and which has proved 

 somewhat destructive in parts of Algeria. It causes a premature falling of the 

 leaves and bolls, and its presence is largely indicated by the roughened, brown, 

 warty condition of the leaves, which bear spots with grayish centers surrounded 

 by violet. 



An examination of the lesions failed to reveal the presence of any parasite 

 whatsoever. The palisade parenchyma and the spaces between were much 

 thickened in the affected areas. The authors think the disease is due to physio- 

 logical causes, such as sudden variation in temi^erature, humidity, etc., agreeing 

 in this respect with the claim of Ducomet regarding brunissure of grapes ( E. S. 

 R., 12, p. 260) . 



Control of blackleg disease of the potato, W. J. Morse (Blaine Sta. Bui. 

 191,, pp. 201-228, pi. i).— In a previous publication (E. S. R., 23, p. 248), the 

 author discussed the character, appearance, distribution, and economic impor- 

 tance of the blackleg disease of the potato. 



This disease has been investigated extensively in Europe and is attributed to 

 a number of different species of bacteria. For the purpose of the present 

 report the author considers blackleg a type characterized by the blackening of 

 diseased tissues rather than a term applied to a single disease caused by a 

 specific organism. 



Investigations on the control of the disease have been carried on in which 

 tubers were submitted to drying, exposure to simlight, various fungicides, etc. 

 Drying and exposure to sunlight were found to kill the organisms, and the 

 treatment of the tubers with disinfectants was followed with good results. 



