DISEASES OF PLANTS. 53 



was done the flowers by the soda Bordoaux mixture. The neutral eopi)er ace- 

 tate and the other preparations were quite injurious, in some instances two- 

 thirds or more of the flowers being destroyed. 



Experiments in combating- the downy mildew of the grape, G. LiJSTNEB 

 (Bcr. K. Jjcliniiist. ]\ < in, Ohst. it. (laitniJxta (lrisnili<ini. l'Jin\ pp. 3.'i2-3.'t5). — 

 The results are given of a series of exi)erinients with solutions and powders 

 for "^he control of grape downy mildew. The powders were tested to determine 

 wheher they could be i)rofitably substituted for liquid fungicides, and also as 

 to their effect in protecting the flowers and fruit against infection and as to 

 the value of combined spraying and dusting for the prevention of mildew. 



Three applications were given all the vines, and the relative efficiency of the 

 fungicides was determined by an examination of the leaves some six weeks 

 after the last aiiplication. The best results were obtained with a 1 and 2 per 

 cent solution of what is called Runun's copper preparation, closely followed by 

 1 per cent Bordeaux mixture. Following these lots were those dusted with 

 Kordlinger's copper mixtures, copper sulphate diluted with silicate of aluminum 

 and magnesia, with talcum, and with kaolin. For the most part, there appeared 

 to be no advantage in combining Bordeaux mixture with any of the powders. 



Is arsenical spraying" killing' our fruit trees? E. D. Ball (Gem State 

 Rural, IJ, (1909), Xo. 10, pp. 6-8). — In an address before the Utah State Horti- 

 cultural Society the author reviews a bulletin of the Colorado Station (B. S. R., 

 20. p. 452). He concludes that instead of the injury being due to arsenical 

 sprays, alkaline ground water and collar rot are the principal causes. Trees 

 in widely distributed areas and on which no arsenic has ever been used are said 

 to have been killed, the symptoms being identical with those described in the 

 above bulletin. The author concludes that arsenical poisoning is not the under- 

 lying cause of the destruction of the trees. It is also pointed out that in the 

 bulletin it is stated that the trees were sprayed with soluble arsenite, a com- 

 pound which is seldom used for spraying purposes. 



A note on one of the coconut diseases, J. H. Hart (Proc. Agr. ,S'or. Trinidad 

 and Tobdf/n, 9 (1909), No. 2, pp. 60. 61). — The author states that the petioles of 

 leaves of a coconut tree showing the perithecia of a fungus were placed in his 

 hands for examination, and a subsequent study showed that the fungus is prob- 

 ably that described under the name Botryodiplodia. 



Spores of this fungus when placed on a fresh cacao pod resulted in the pro- 

 duction of appearances exactly corresponding with the brown rot of cacao, due 

 to Diplodia cacaoicola, the pod rotting in the same manner. Some slight dif- 

 ferences were noticed in the size of the spores, but otherwise the fungi on both 

 hosts are believed to be closely allied, if not identical. The fact that a dis- 

 eased cocouut tree is able to infect cacao pods and cause a disease identical 

 with brown rot is of interest in showing methods of infection which have not 

 previously been recorded. 



The oak mildew, E. Fischer (^^chicciz. Ztschr. Forstw., 60 (1909), Xo. 1, 

 pp. 10-15, figs. .'/). — The author gives an account of the mildew that was so con- 

 spicuous in 1008 on different species of oaks, and discusses the probable rela- 

 tionship of the fungus, the oidium stage of which was the only form observed. 



Some wood-destroying fungi, O. Bittmann (Osterr. Forst u. Jagd Ztg., 27 

 (1909), yo. 10, pp. s.'i. So. Jigx, 30). — Illustrated notes are given on a number of 

 parasitic and saprojihytic fungi which are known to attack deciduous trees. 



Some obscure gall diseases, R. Laubkrt (Deut. Landiv. Prcsse, 36 (1909), 

 A'o. 19, pp. 211, 212, figs. //). — Descriptions are given of some unusual gall for- 

 mations on oaks, birches, and roses, the causes of which are not definitely 

 known. 



