DISEASES OF PLANTS. 53 



Barley smut invastigations, K. A. .Moore and A. L. Stone ( Wii<roiisin Sta. 

 Rpt. 1907. 1)1). 'fOi), .'/lO).- — 111 the experiuieiits being coiulueted by the autliors with 

 a view to reducing the loss from barley snuit, the moditied hot-water treatment 

 was again used during 1907 with practically the same resnlts reported for 1906 

 (E. S. R., 18, p. 1055). Owing to the cold weather following the seeding, some 

 of the kernels of soaked barley failed to germinate and in some places the stand 

 was thinner than on plats wher^ the seed was not treated. 



Data received from 99 members of the experiment association, who condncted 

 cooiierative tests in exterminating smut, show an average percentage of smut in 

 untreated seed of 2.93 as compared with an average of only 0.65 per cent of 

 smut in treated seed. The average percentage of the crop saved by the treat- 

 ment was 2.2S. Thirty reported i>oor germination of treated seed after sowing. 



As a result of both the station and cooiierative tests, it is concluded that loose 

 smut of barley can be eradicated by the modified hot-water treatment, although 

 the farmer is advised to treat only small areas until further tests have been made 

 with large quantities of seed. The range of temperatures of the hot water at 

 which the ti'eatment will be effective without injury to the seed appears to be 

 limited. Treated barley should be sown immediately, otherwise it will sprout. 

 The ground should liave become warm before sowing, to facilitate germination. 



Observations upon the prevalence of early potato blight (Alternaria 

 solani) in Wisconsin, ,J. G. Milward (Wiscon'<in Sta. Ri)t. 1907. pi). S'/SSoO. 

 figs. 6). — The potato investigations conducted by the station for the past 4 

 years have shown the early potato blight (A. solani) to be an immediate factor 

 in determining the annual yield of potatoes in Wiscousiii. The author points 

 cut the need of a correct understanding of the nature and life history of this 

 fungus and a clear correlation of these facts as associated with standai'd 

 methods of control. The disease is briefly discussed relative to conditions lead- 

 ing to its develojiment and perpetuation, and the iniiK)rtant moriihological char- 

 acters of the fungus are brought out by the aid of illustrations. 



Potato spraying experiments for 1907, J. (4. Milward ( Wiscon.sin tSta. Npt. 

 1907. i)p. 351-35Ji, fig. 1). — The spraying experiments for the prevention of early 

 blight were continued during 1907 with results similar to those reported for 

 1905 and 1906 (E. S. R., 18, p. 10.56). 



Bordeaux mixture has proved an efficient preventive where cultural condi- 

 tions are suited to the growing of the crop, 5 applications of Bordeaux made dur- 

 ing the season on each of the 3 test fields at a cost of $4..30 i)er acre resulting 

 in gains per acre of 27, .30, and 52 bu. of potatoes, respectively, and net profits 

 per acre of $7.70, $9.20, and $21.70, resjiectively. 



The work has beeu extended to include observations upon lilight-resistant 

 varieties and yield tests with 3 varieties of Russian alcohol potatoes. Among 

 the 110 varieties tested a wide variation was shown in regard to disease resist- 

 ance. 



Attention is called to the importance of selection and care of seed potatoes 

 as a factor in maintaining productiveness and vigor in the standard varieties, 

 and to the need of a closer study of the influence of weather conditions upon 

 the prevalence of early blight in Wisconsin. 



Diseases afEecting rice in Louisiana, H. R. Fulton {Loidskuia Stas. Bui. 

 JO.'), pp. 3-2H. pis. 8). — Four diseases of rice observed in Louisiana are con- 

 sidered in this bulletin, the blast, brown grain spot, green smut, and black 

 Rmut. 



The first disease, rice blast, is in all probability the same as that known in 

 Italy as brusone, and also known to occur in .Japan, and is caused by the fungus 

 I'iricuJaria oiyzce. The general effect of the blast is shown in the extensive 



