DISEASES OF PLANTS. 479 



The effect of the fungus on the host plant, as well as its character as shown in pure 

 cultures, is described. For the prevention of the disease the author recommends spray- 

 ing the potatoes throughout the season with Bordeaux mixture at intervals of 2 or 3 

 weeks. After the potato harvest it is suggested that the tops should he collected and 

 burned, and attention paid to the use of fertilizers and manures. - Deep plowing of 

 the potato field after harvest is suggested as a beneficial practice; and potatoes should 

 not be continued in the same field for any long period of time, since the fungus is 

 liable to become established in the soil, where it is able to pass the winter. 



Some diseases of the potato, G Massee (Queensland Agr. Jour., 15 {1904), 

 No. /, ]>/>. 605-607). — A summary is given of an article published by the author in 

 Gardener^ Chronicle relating to some of the diseases of the potato. Among those 

 described are the potato rot (Phytophthora infestans), winter rot (Nectria solani), 

 black seal) (CEdamyces leproides), bacterial disease (Bacillus solanacearmn) , and potato 

 scab (Sorosporium scahics). 



Treatment of potatoes with fungicides, F. Parisot (Jour. Ayr. Prut., n. ser., 8 

 (1904), No. 34, pp. 234, 235). — In a series of experiments carried on at Rennes 4 

 varieties of potato were grown in different lots, one lot in each case being treated 

 with Burgundy mixture, containing 2 per cent copper sulphate, and the others 

 remaining as checks. 



The results of the treatment showed that in the case of 3 varieties there was a 

 difference in favor of the treated plants, varying from 7 to 50 per cent, while with the 

 fourth variety there was a loss of 24 per cent. It appears from these investigations 

 that spraying early or semiearly varieties is attended with good results, but when 

 the variety of potato grown is a very late one the author's experiments showed a 

 positive loss. These results are in line with those quoted from experiments by 

 Aime Girard, who found that very late varieties were less influenced by spraying 

 than medium or early varieties. 



Sugar-beet diseases, W. H. Hutt (Utah Sta. Rpt. 1903, pp. XXII-XXYI). — An 

 account is given of cooperative experiments arranged with this Department in which 

 the effect of different fertilizers in checking sugar-beet diseases was investigated. 

 The disease in question w r as first noticed in 1902 and seemed to be very destructive 

 wherever observed. 



On examination of the fields a few beets were found which seemed to have resisted 

 the disease, and these were placed in a silo with the expectation of raising strains of 

 beets which might be immune to the disease. The rot, however, continued through- 

 out the winter, and of several bushels which were stored but one beet remained to 

 bear seed. As the disease did not appear at all during 1903 the experiment resolved 

 itself simply into a test of the value of different fertilizers for raising beets. 



The yellowing of sugar beets, G. Delacroix (Compt. Rend. Acad. Sci. Paris, 

 137(1903), N<>. 21, pp. 871, 872; extr. from Sucr. Indig. et Coloniale, 62 (1903), No. 22, 

 l>p. 13). — A description is given of a bacterial disease of beets which has been under 

 observation for some time. The author has isolated the organism causing the disease 

 and studied its characters, and he proposes for it the name Bacillus tabificans. The 

 distribution of the disease, its characteristics, and methods of attack are described 

 and notes given on experiments for combating it. 



As a preventive treatment the author recommends at least a 3-years' rotation of 

 crops, the use of no seed that is 4 years or more old, the careful exclusion of all 

 volunteer crops on fields where beets have been cultivated, and care in the 

 application of manures that none should come from animals fed with diseased beet 

 leaves. 



A disease of asparagus, G. Delacroix {Extr. from Bui. Mens. Off. Renseignements 

 Ayr., 1903, pp. 6).— The author describes a disease of asparagus which is attributed 

 to the well-known fungus Rhizoctonia violacea. 



