548 EXPERIMENT STATION RECOED. [Vol. 43 



seeius to be a carrier of the infection. Inoculation experiments wore con- 

 ducted in whicii juice from diseased plants was transmitted to sound cane and 

 the diseased condition produced. It is con.sidered tJiat the cell sap of diseased 

 I)lants is infectious when Introduced in the proper manner, and that the 

 disease can be transmitted by insects. Just wliat insects are responsible for 

 dis.semination in the cane regions remains to be proved. 



[Matizado or mosaic of sugar cane], F. S. Earle (Rev. Agr. Puerto Rico, 

 2 (1918), No. 1, pp. 5-10). — A rfeume is given of what is known regarding the 

 characters and effects of sugar-cane mosaic, now widely distributed In this 

 region. 



Matizado of sugar cane, J. A. Stevenson (Rev. Agr. Puerto Rico, 2 (1918), 

 No. 1, pp. 51, 52; 2 (1919), No. 2, pp. 11, i2).— Matizado of sugar cane is said 

 to be caused by a virus or an ultranucroscopic oz'ganism wluch may be trans- 

 mitted by insects or other means. Certain varieties appear to be somewhat 

 resistant. Conti'ol measures recommended include seed selection, destruction 

 of infective material, and breeding of resistant varieties. 



[Sieve tube disease of sugar cane], P. van Harreveld (.1 /(•/(. SuikerindtLs. 

 Nederlhnd. Indie, 26 (1918), No. 9, pp. 333-346; also in Meded. Proefsta. Java- 

 Suikerindus., Landbouick. Ser., No. Jf (1918), pp. 333-3^6). — This is lai-gely a 

 discussion of recent study and opinion regarding sieve tube di'Sease of sugar 

 cane, and regarding its probable causation by Bacillus rascularum. 



[The causation and prevention of sieve tube disease], P. van Harreveld 

 (Arch. Suikeritidus. Nederland. Indie, 26 (1018), No. 13, pp. 527-531).— It is 

 claimed that sieve tube disease has been shown by C. A. H. von Wolzogen 

 Kiihr to be due to Bacillus vascularum, and that the chief protective measures 

 at present availal)le are preventive, such as control of importation of planting 

 material. 



Mosaic of tobacco, J. A. Stevenson (Rev. Agr. Puerto Rico, 2 (1918), No. 1, 

 pp. 39-44). — This brief account dealing with the symptoms, causation, preven- 

 tion, and other modes of control of tobacco mosaic states that the disease 

 (apparently due to an ultramicroscopic organism) is transmitted by insects, 

 by contact of implements and clothes, and by other agencies. 



Notes on some tomato diseases, C. R. Orton and W. H. McKinney, jr. 

 (Pennsylvania Sta. Rpt. 1916, pp. 28.5-291, pis. 4)- — Accounts are given of a 

 number of tomato diseases observed by the authors during their three years' 

 study of the disease known as winter blight that occurs in greenhouses. The 

 purpose of tlie present publication is to call attention to these diseases and to 

 control measures which may be of value to growers. 



Among abnormal conditions reported upon is one designated as bull plants. 

 These are distinguished by faster growth, greater height, the leaves being 

 much larger than in normal tomato plants and the foliage usually darker 

 green. These plants have not been observed to bloom and in all their study no 

 fruit was produced by them. The removal of the plants as soon as they are 

 noticed is reconnuended. 



A second disease reported upon is the curly top or rosette. Plants affected 

 by this disease are usually not detected until they are a foot or more in height. 

 At this time the stalks appear thicker and there is a strong tendency for the 

 leaves to be clustered at the top of the stalk. The leaves are numerous and 

 smaller, being noticeably shorter, thicker, and conspicuously curled. Diseased 

 plants are said to blossom rarely and were never observed to set fruit. An 

 examination of the root system for parasites was made, but none were found. 

 Plants affected by curly top are said to be as susceptible as normal plants to 

 mosaic 



