DISEASES OF PLANTS. 381 



the rejection of all which show any traces of disease, and rotation of crops so that 

 -endive shall not he cultivated in the same ground for 2 years in succession. 



The scab of potatoes ( Bui. Mens. Off. Renseignements Agr., 3 (1904), No. 8, pp. 924, 

 925). — A brief account is given of the black scah of potatoes, due to CEdomyces lep- 

 roides or Chrysophlyctis endoMotica, the information being largely based upon publi- 

 cations of the Board of Agriculture of England. 



The diseases of the potato in relation to its development, L. R. Jones (Ann. 

 Rpt. New Jersey State Bd. Agr., 31 (1903) pp. 163-175, figs. 8).— This is a lecture deliv- 

 ered by the author, and is based on investigations carried on at the Vermont Station, 

 all of which have been noted elsewhere. 



The biology of Phytophthora infestans, L. Matrcchot and M. Molliard (Ann. 

 Mycol.,1 (1903), pp. 540-54-:: abs. in Bot. Centbl, 95 (1904), No. 6-7, p. 158).— Biological 

 .studies are given of the potato rot fungus (PhytopMhora infestans). The fungus was 

 grown on a number of media, including sliced potatoes, cucurbits, etc., and on arti- 

 ficial media of various kinds. The best spore formation was found when grown on 

 natural media, as they are called, growth on an artificial media tending to sterility. 



A bacterial rot of onions (Agr. News [Barbados], 3 (1904), No. 60, p. 245). — 

 A description is given of the bacterial rot of onions, which was noted in Barbados as 

 affecting the inner scales of the bulb after the crop had been gathered and stored. 

 No fungus was found present, but the diseased scales were swarming with bacteria. 

 While not demonstrated, it is believed that this disease is similar, if not identical, 

 with that previously described by F. C. Stewart, of the New York State Station 

 (E. S. R., 12, p. 55). 



Some root-crop diseases in Ireland, T. Johnson' (Jour. Dept. Agr. and Tech. 

 Instr. Ireland, 4 (1903), No. 2, pp. 258-263, figs. 8). — The author describes a disease 

 of mangel-wurzels due to (Edomyces leproides, a dry rot caused by Sphierella betse, and 

 a rot of Swedish turnips caused by Phoma brassicse. 



Disease of sorghum in the Madras Presidency, C. A. Barber (Dept. Land 

 Records and Agr., Madras, Vol. II, Bui. 49, pp. 273-288). — Descriptions are given of 

 some of the fungus and insect injuries to sorghum, particular attention being given 

 to sorghum smut, 2 forms of which are described as due to Ustilago reiliana and U. 

 tulasnei. For the prevention of these diseases, the author recommends immersing 

 the seed grain in a copper sulphate or a formalin solution prior to planting. Other 

 diseases due to ColletotricJium falcatum, Puccinia penniseti, etc., are described. 



Experiments for the prevention of black spot or scab of apples, D. McAlpine 

 (Jour. Dept. Agr. Victoria, 2 (1904), Nos. 4, pp. 354-360; 8, pp. 761-767, pis. 9).— A 

 report is given of a series of experiments conducted to test the efficiency of Bordeaux 

 mixture when employed on a commercial scale and also to ascertain the adhesive- 

 ness of various fungicides when used for the prevention of the black spot or scab of 

 apples and pears. The first series of experiments was conducted in 1902-3, followed 

 by a second series of experiments in 1903—4. 



In the first experiments it was shown that with proper spraying with a well-pre- 

 pared Bordeaux mixture the disease could be completely controlled. The additions 

 of common salt, sal ammoniac, etc., while slightly increasing the efficiency of the 

 fungicide, are not believed to be necessary. The second season was generally favor- 

 able for the development of fungus diseases, and in many instances the attacks were 

 prolonged unusually late in the season. In a large number of orchards a second defi- 

 nite period of infection was observed after the usual primary infection. As in the 

 previous experiments the disease was found to be readily controlled by the use of 

 Bordeaux mixture, and from the results obtained a 6 1 40 formula is preferred. 



A precocious decay of Botrytis in Algeria, L. Trabvt (Bui. Agr. Algirie et 

 Tunisie, 10 (1904), No. 11, pp. 229-232, figs. 2). — An account is given of an unusual 

 decay of Botrytis cinerea on grapes in Algeria in which the flowering clusters, early 

 foliage, young shoots, etc., were badly infested. 



