DISEASES OF PLANTS. 1141 



This WMS iK'lk'ved to l»e of biu-li'ri.il origin and was so rcportod by Clinton 

 in T.X)3 (E. S. !{.. 16, p. G2). The disease Wiis asain noticed in lOon, and in 

 !!)()(>, 1907, and 1008 the author undertook a detailed study of it throuKhoufr 

 the South and Middle West. lu these sections it proved lo Ik- the c(tniuionest 

 shot-hole disease of peach leaves, the Cercospora leaf sjjot heiuj; l)ut rarely met 

 with. Numerous investi>:ations showed that the disease was of bacterial origin. 

 A bacterial disease of peach twigs and of the fruit was also found, and it seems 

 probable that they, as well as the leaf sjiot, are caused by the same organism. 



During the sunnner of 1007 a series of successful inoculation experiments 

 with the organism was made. There appears to be but little doubt that the 

 organism causing the leaf spot is the same as that described by Smith as 

 liuciciium pniiii. the cause of the bacterial black spot of i)lunis and a ]tlum 

 leaf spot (E. S. H.. 17. 157). 



As the fruit spot was not discovereil until toward the close of the peach 

 season, little work has been done upon it. 



The immunity of Coffea congensis to Hemileia vastatrix, M. Dubard 

 (Jour. Afjr. Ti(>i>.. )i {IDOS). A o. 'JO. /tit. 3U3, SG'i). — A description is given of the 

 variety chaloti of C. vongcuHlK, which is grown at the experiment station at 

 Tamatave, Madagascar, and which has proved to be decidedly resistant to 

 attacks of //. lantatrlr. This variety seems to have originated from seed that 

 has been under observation for a number of years in Madagascar, the original 

 coming from the Kongo region of Africa. The variety seems not only more 

 immune, but is of decidedly better quality than the Liberian coffee, and it is 

 believed that it can still be improved hy breeding experiments. 



Witches' broom disease of cacao, C. J. J. van Hall and A. W. Drost {Rec. 

 Tnir. Hot. Xrcrland., .J {PJOS), No. 'i, pp. 2J,3-310, pis. 11; Jour. Bd. Agr. Brit. 

 Guiana, 2 (1009), No. 3, pp. 126-132; Roy. Bot. Gard. Kcw, Bui. Mi,^c. Inform., 

 I'JO!), No. 5, pp. 223, 22.'f). — A study ou the origin, nature, and treatment of 

 tlie witches' broom disease of cacao as it occurs in Surinam is reported. 



The symptoms of the disease are summarized, from which it ai)pears that the 

 witches' brooms are hypertrophied branches, considerably thickened at the base, 

 with rough surfaces. They are further distinguished by the leaves being small 

 and stunteil. Another form of the disease is characterized by the hardening 

 of the pods, a symptom not originally associated with this disease, but usually 

 attributed to the fungus I'lii/tophlltora oninicora. The third manifestation of 

 the disease is what is designated as " star flowers." These are borne on fruit 

 branches which present the same pathological symptoms as the witches' brooms, 

 but they appear as an agglomeration of a large number of flowers, having 

 among them vegetative branches transformed into small witches' brooms. They 

 seldom give rise to ripe i»ods. 



The disease, accoi-ding to the author.s, has been found to be due to the fungus 

 C'()llctotriclnnn lu.iiflcunt, a description of w'hich is given. 



The effects of the disease are chiefly shown in the reduction of the crop, and 

 for its prevention severe pruning, after which the trees are to be sprayed with 

 liordeaux mixture, is recommended. The pruning in some of the experiments 

 amounted to pvactically the cutting away of the entire top of the tree, after 

 which all the diseased material was burned. This drastic treatment resulted 

 in the practical loss of the crop for a year or two, but the tree recovered, and in 

 a few yeai's had grown wt'll-developed tops. 



So far as the authors' investigations go, other species of trees are not subject 

 to the attack of this species of Colletotricluuii. as has been currently re|>orted. 



Root rot, A. Despklssis (Jour. Ihi,l. Ai/r. \\'<sl. Aiisl.. 17 (/.<W,S). .Vo. /. pp. 

 ■'iJ '/-.') >i If. Ills. 2). — According to (lie author, consideral)le trouble is reported in 

 different parts of West Australia, due to the root rot of various orchard and 



