DISEASES OF PLANTS. 1083 



given on recent investigations in many tropical conntries of some of the more imi)or- 

 tant diseases of economic j^lants. Among tliosc reviewed are the diseases and insects 

 affecting coffee, cacao, tea, sugar cane, cotton, pineapples, l)ananas, citrus fruits, 

 rubber trees, and cork oalc. 



Notes on some plant diseases, K. Malkofp {Ztfichr. J'flanzenlrank., 12 {1902'), 

 No. 5, pp. 283-285, fig. 1) . — Brief notes are given on a number of diseases of plants 

 which the author observed in the vicinity of Gottingen. The first described is the 

 anthracnose of clover due to Gkwsporium cauUvorum. The author claims that red 

 clover grown from seed from different countries seems to be unequally affected, that 

 from eastern North America being most subject to disease, while the south Russian, 

 Polish, and Canadian was least attacked. In addition to the red clover, tlie author 

 reports the fungus as attacking Trifoliinn jmrpureum and T. medium. The early 

 mowing of clover fields is recommended to prevent the spread of the disease. A 

 second disease which also attacks clover is due to the fungus Macrosporium sm-fimr- 

 forme. This fungus attacks the leaves, giving them a ragged appearance and later 

 causing them to turn brown and fall from the plants. Inoculation experiments were 

 carried on with cultures of this fungus which seem to demonstrate that it was due 

 to this particular organism. The third disease described is that of leaf spot of rye, 

 caused by the presence of ItJnpicJiosporintn graminlcold. The extent of injury due 

 to this cause was not determined. 



The distribution of the anthracnose of red clover, G. Linhart {Zt.'icJir. 

 Fjldiizcvlrank., 12 {1902), No. 5, 2>p. 2S1, ^.9^').— The distribution of Gla'oxporium 

 cauUvorum, the cause of clover anthracnose, or stem browning, as it is called, is said 

 to cover practically all of Europe wherever red clover is grown. The author says 

 that plants grown from American or European seed suffer alike and in some places 

 as much as 50 per cent of the plants were observed to be dead as a result of the 

 fungus. Weather conditions are said to exert an important influence on the occur- 

 rence of the diseases, unusual wet w^eather greatly favoring its spread. So far as 

 the author's observations go, alfalfa does not appear to be subject to this disease. 

 The fungus attacks all of the above-ground parts of the plant, the stems and petioles 

 in particular, causing them to turn brown as though burned. There is thought to 

 be some evidence of the transmission of the disease by means of infected seed, and 

 it is recommended that seed be treated with a 1 per cent solution of Bordeaux mix- 

 ture before sowing. 



Investigations on cereal rusts, E. Maechal {Bui. Agr. \_Brussels'], 19 {1903), 

 No. 1, pp. 114-158). — After briefly reviewing the present status of the cereal rust prob- 

 lem the author gives descriptions of the more common species which he has investi- 

 gated. Among those described are the black rust { Puccmia graminis) , brown rust 

 {P. friticina), yellow rust of wheat (P. glumarion), brown rust of rye {P. dkpcrsa), 

 pale rust of barley {P. .vmplcx), and crown rust (P. coronifcra) . Most of these rusts 

 have specialized forms which are also described. Analytical keys are given for the 

 determination of the kind of rust found upon a plant, and a tabulated statement is 

 presented showing the distribution and frequency of occurrence of the different 

 species in Belgium. 



The author states that wheat is most frequently attacked by the brown rust, fol- 

 lowed by the yellow and black rusts in order of frequency. The figures upon which 

 this conclusion is based are the averages of observations made during 2 seasons 

 although slight differences are noted, particularly in the relative occurrence of the 

 yellow and black rusts. Upon the rye the principal species is the brown rust, the 

 black rust l)eing rather rare and spasmodic in its appearance. The common ])arley 

 rust is the pale rust whic^h was found present in 92 per cent of all the specimens 

 examined. The black rust is frequent in certain years, while the yellow rust which 

 is so destructive in Sweden is unknown in Belgium. The oats suffer most from the 

 crown rust, and the black rust is comparatively rare. The varying susceptibility of 



