DISEASES OF PLANTS. 851 



It is recommended that all importations be strictly inspected to guard against 

 further spread of the disease. Infected plants or parts are to be destroyed by 

 fire and neighboring vegetation to be sprayed 3 or 4 times with 0.4 to 0.5 i^er 

 cent potassium sulphate solution, or preferably 2 per cent copper-lime solution. 

 Severe cutting back late in the fall and burning of prunings are recommended, 

 with application of quicklime to the soil surface and of 2 per cent milk of lime 

 to the plants, these ;!pplications being repeated in the spring. Suggestions are 

 made also regarding the employment of fertilizers which have been found help- 

 ful in combating this disease. 



The Surinam witches' broom disease of cacao, J. B. Rorer {Bd. Agr. Trini- 

 dad and Tobago Circ. 10, 1913, pp. i3).— Pursuant to a previous communication 

 (E. S. R., 23, p. 455) the author gives the results of two series of studies recently 

 made by him on witches' broom of cacao, concluding that this disease is of 

 fungal origin, probably due to a basidiomycete. It is thought that it can be 

 controlled by spraying vAdth Bordeaux mixture, which is considered a more 

 rational method of treatment than the severe cutting back recommended by 

 van Hall and Drost (E. S. R., 20, p. 1141). 



Coffee disease in East Africa (Roy. Bot. Gard. Keio, Bui. Misc. Inform.. 191S, 

 No. 5, pp. 16S-171). — The recent recognition in Uganda of the coffee disease 

 caused by Eetnilcia vastatrix has necessitated a reexamination of the Hemileia 

 material which has reached Kew from time to time from Tropical East Africa. 

 Careful comparison of that material with type specimens of both H. vastat?-i.r 

 and H. ivoodii has also been necessaiT- The chief result of the examination is 

 said to be the establishment of the fact that there is no record of coffee being 

 attacked by any species of Hemileia other than H. vastatrix. 



The resistance of a variety of Helianthus annuus to Orobanche cumana, 

 T. Satsypebov (Trudy Bvuro Prikl. Bot. (Bui. A^igcw. Bot.), 6 (1913), No. .',, pp. 

 251-261). — The results of experiments carried out at the Saratov Experiment 

 Station in 1912 are said to show that the variety of H. annuus in question pos- 

 sesses a high degree of resistance to O. cumana. 



Notes on some diseases of trees in our National Forests, III, G. G. Hedgcock 

 (Phytopathology, 3 (1913), No. 2, pp. lll-lllt).—ln continuation of a previous 

 report (II S. R., 27, p. 653), the occurrence of Polyporus dryophilus or a closely 

 allied species as a cause of a disease of the heartwood of the aspen (Populus 

 tremuloidcs) is reported in some portions of Ck)lorado. Armillaria mellea is also 

 said to attack the roots of many species of trees both in the eastern and western 

 forests. 



Notes are given on the winter and frost injuries to trees and on smelter 

 injury to forests. This latter is in continuation of a previous report (E. S. R., 

 26, p. 826). The author has found that the belt of acute smelter injury in the 

 Deerlodge National Forest in the vicinity of Anaconda, Mont., has been greatly 

 extended during 1911 and 1912. The limber pines on hills adjacent to the 

 smelter show an acute form of smelter injury and are slowly dying. An exami- 

 nation of the limber pines, even at a distance of 10 miles from the smelter, 

 showed a gradual diminution of growth in the accretion rings, an^i it is thought 

 that under the existing conditions there is no hope of natural reforestation. 



Notes on diseases of trees in the southern Appalachians, I, A. H. Graves 

 (Phytopathology, S (1913), No. 2, pp. 129-139, figs. iO).— This is the first of a 

 series of articles in which the author expects to give the results of an investi- 

 gation on the diseases of trees in the southern Appalachians. In this paper 

 some diseases of white pine are described, among them bark blight due to 

 Coccomyces pini, heart rot caused by Trametes pini, and leaf blight attributed 

 to Lophodermium brachy-iporum, 



