DISEASES OF PLANTS. 645 



The bacteria causing the disease have beeu isolated and artificial inoculatious 

 made which indicate that they are the cause of the trouble in question. Some 

 varieties were found to be naturally immune, and the planting of such is ad- 

 vised. There appear to be two slightly difl'erent kinds of bacteria concerned in 

 this trouble, and in addition to blighted buds and spurs, cankers are formed 

 on the branches, limbs, and trunks of trees. 



The method of dissemination of the trouble is unknown, but indications point 

 to the possibility of sucking in.sects being among the carriers of the bacteria. 

 The most serious infection is believed to take place in the autumn, the new 

 infection developing slowly at first, and late in winter and early in spring 

 becoming of very rapid growth. Wound parasites and wood rotting fungi fre- 

 quently enter at the cankered spots and extend the injury originally caused by 

 the bacteria. 



A similar canker disease has beeu found on prunes, peaches, and apricots, 

 and pathogenic bacteria apparently identical with the organisms found on 

 cherry trees were isolated. 



Suggestions are given for the control of the disease, which include the plant- 

 ing of resistant stocks to be later grafted to commercial varieties, and cutting 

 out of all diseased material. 



Experimental spraying' of prunes for control of brown rot, F. D. Bailey 

 (Oregon 81a. Bicn. Crop Pest and Hort. Rpt. 1913-lJf, pp. 2Jfl-2.'fJ,).— The results 

 of spraying experiments carried on in 1913 and 1914 for the control of the 

 brown rot of stone fruits are given. 



In 1913 four spray mixtures were tested, Bordeaux mixture. Burgundy mix- 

 ture, self-boiled lime sulphur, and commercial lime sulphur. Two applications 

 were given of all except the Burgundy mixture. The results seemed to indicate 

 that for the earlier attack Bordeaux mixture gave the best results, while the 

 second record showed a greater loss than with the check in all cases except 

 where self-boiled lime sulphur was employed. 



In 1914 the work was repeated, and comparing the results obtained both sea- 

 sons it is considered probable that Bordeaux mixture will be found as satis- 

 factory as any spray for the control of this disease. The best time of appli- 

 cation of the fungicides was found to vary with conditions that are not clearly 

 understood. 



A Pacific Coast rust attacking pear, quince, etc., H. S. Jackson (Oregon 

 Sta. Bien. Crop Pest and Hort. Rpt. 1913-14, pp. 204-212, figs. 3). — This is a 

 detailed account of the attack of Oymnosporangiuni hJasdaleanum on quinces, 

 pears, etc., a preliminary notice of which has already been given (E. S. R., 32, 

 p. 51). 



A bibliography is given. 



Varietal resistance of the gooseberry against mildew and the effects of 

 sulphur treatment therefor, G. Kock (Ztschr. Landw. Versuchsw. Osterr., 17 

 (1914), ^0. 6-7, pp. 634-637).— Ot about 100 varieties of gooseberry tested, about 

 16 proved to be susceptible to American gooseberiy mildew, while 56 proved to 

 be susceptible to injury from treatment with powdered sulphur for the pre- 

 vention of the disease. 



Fungus diseases of coffee in Porto Rico, G. L. Fawcett (Porto Rico Sta. 

 Bui. 17 (1915), pp. 29, pis. 8). — A discussion is given of the commoner and more 

 destructive diseases of coffee in Porto Rico, among which are the leaf rot or 

 thread blight due to Pelliculana koleroga, the leaf spot caused by Stilbella 

 flavida, root diseases due to RoseUinia sp. and Dematophora sp., and berry spot 

 caused by Cereospora coffeicola. These diseases are described at considerable 

 length and the results of investigations for their control are given. 



