374 EXPERIMENT STATION RECORD. 



Investigations on the black shank of potatoes, O. Appel {Arb. K. Gesund- 

 h('il>f(iiitt( , llinl. Aht., o (lUO.S), Xo. .'/, pp. o>;4-/f,lJ, pi. Ijjiy.s. 15). — The author gives a 

 desorij:)ti()n of a bacterial disease of potatoes due to a iiitherto undescribed s[)ecieR, 

 B(tcilhi:< pluitophtltorui^. This organism causes what is known as black sliank of the 

 stems and the rotting of the tu})ers. The attack on the stems is most apparent near 

 the ground. The stems are blackened and become rotten; hence the name black 

 shank or stem rot. Later the tubers are affected, being rendered useless by the rot. 



The organism, which is fully described, is said to be quite distinct from B. solana- 

 cearum, widely known in this country. Numerous infection experiments in the 

 laboratory and field have been made which show the infectious nature of the disea.se. 

 Inquiries were instituted on the distribution of this disease, and from the replies 

 received it was found to be quite generally distributed throughout Germany. 

 Marked differences in the susceptibility of varieties of potatoes are noted, and experi- 

 ments are reported which were carried on to test the ability of the organism to live 

 on other host plants than potatoes. The bacteria were found capable of infecting 

 horse beans, lupines, carrots, certain varieties of turnips, cucumbers, etc. 



Soaking the seed tubers in Bordeaux mixture was found to reduce the amount of 

 disease considerably but not entirely. As practical suggestions for combating this 

 disease the author suggests a rotation of crops in which neither potatoes nor any of 

 the above-mentioned crops should occupy the ground for a number of years, the 

 planting of whole potatoes, disinfecting them with fungicides, and the avoiding of 

 strong nitrogen fertilizers, especially Chili saltpeter and ammonium sulphate. 



The infection of sug-ar beets by Rhizoctonia violacea, F. Bubak {Ztsclir. 

 Zuckerind. Bohmen, 190S, No. 8, pp. 5; ahs. in Bot. fhifbl., 9.3 {190S), No. 34, p. 

 193). — During 1901 and 1902, sugar beets in Central Bohemia were attacked by the 

 root-rot fungus Rhizoctonia violacea. In one locality, at least 15 per cent of the beets 

 was destroyed by the disease. It was not definitely determined whether the infec- 

 tion was through the soil or introduced through spores upon the seed when planted. 

 The author recommends for the prevention of the disease treating the soil with quick 

 lime, better attention to drainage, and a rotation of crops so that beets will not be 

 cultivated more than once in 4 years. 



The rind disease of sugar cane in the West Indies, A. Howard {Internal. 

 Sugar Joiir., 5 {1903), No. 53, pp. 215-2.25, pi. 1). — The results of several years' 

 study of the diseases of sugar cane are given, particular attention being devoted to 

 the so-called rind disease. This disease in the West Indies is said to be identical 

 with the red smut disease of Java, and is caused by the fungus Colletotrichum falcatum. 

 This fungus is able to infect ripening canes at wounds and old leaf bases, and can 

 attack the young canes in any of the rapidly growing tissues. The Melanconiuni 

 found on diseased sugar canes in the West Indies is a saprophyte and is not to be 

 considered as a cause of the rind disease, but readily attacks plants which have been 

 Aveakened l)y the Colletotrichum. Experiments have shown that the destructive- 

 ness of this disease may be reduced by burning the diseased canes at time of harvest, 

 stripping the growing canes, planting from the best cuttings, and controlling the 

 cane-boring insects. 



The Sereh disease in the West Indies, F. A. F. C. Went {Indische Mercuur, 

 25 {1903), Jlerinnering.snmnmer, p. 19; ahs. in Bot. Centhl., 93 {1903), No. 29, p. 66). — 

 The author reports the presence of the Sereh disease in the cane fields of the West 

 Indies and northern South America. From the leaf sheath of stalks has been taken 

 the Verticil liuni form of ITupocrea sacchari, which seems to substantiate the author's 

 hypothetical relationship between the Sereh disease and this fungus. 



A bacterial disease of tobacco, G. Delacroix {Jour. Agr. Prat*, n. .?er., 6 {1903), 

 No. 3S, j>p. 385, 386). — A preliminary account is given of the bacterial disease of 

 tobacco which has been observed in a lunnber of regions in central France. The 

 first appearance of the disease was noted in July when the plants had attained a 



