DISEASES OF PLANTS. 261 



entirely destroyed. Prior U> the death of the trees the foliage assumes a yellowish 

 api)earance and the diseased bark becomes cracked and loosened from the trunk. 

 Experiments were conducted for the prevention of the disease, in which the loose 

 bark was removed from the affected i^ortions of the trees, after which the scraped 

 areas were covered with a copper- whale-oil soap mixture, a mixture of formaldehyde 

 and glycerin, and a Bordeaux-resin soap mixture. The directions for the prepara- 

 tion of the different fungicides are given, and as a result of the treatment the formal- 

 dehyde-glycerin mixture is recommended as jiromising and worthy a more extended 

 trial. 



An experiment is rei)orte<l in which the i^rotection of pear trees against blight by 

 spraying with a lime-sulphid solution was investigated. As there was only a slight 

 amount of blight observed during the season, the results obtained are of a negative 

 nature. The same experiment i^ to be repeated during the coming season. 



On account of the frequent rotting of plums, even when thickly coated with 

 Bordeaux mixture, an experiment was conducted in which the fruit was incased in 

 paper bags some time before ripening, the object being to ascertain the time of 

 infection of the fruit and the etRciency of this method of protection. C'overing the 

 plums with bags slightly diminished the amount of rot, but not to any material 

 degree. Plums covered by bags and protected against insect punctures during the 

 susceptible period of infection showed from 36 to 91 per cent rotten fruit. In a 

 number of experiments the fruit was thii'kly covered with Monilia spores before 

 bagging but this treatment did not markedly increase the amount of rot. From 

 these exjieriments it is concluded that plums become infected through other chan- 

 nels than by the direct infection of the fruit itself, and this explains why the fruit so 

 fre(iuentl,v rots when thickly covered with Bordeaux mixture or other fungicide. A 

 cooperative experiment is reported in which a Bordeaux-resin mixture was sprayed 

 over plum trees to protect against the rot. After spraying, the trees were inspected 

 at intervals, and although the fungicide was plainly visible covering the fruit, the 

 percentage of rotten plums was very high, the fungicide offering little if any 

 protection. 



Notes and observations on plant diseases, 1901, J. Percival [Jaur. Suulli- 

 cdi^t. Af/r. Col., Il/zr, lf)0:J, No. :J, p}>. 81-89, figs. S). — The author reports the observa- 

 tion of a nundjer of plant diseases during the season of 1901. Among those 

 mentioned are the barley smuts, due to UstUago nuda and U. jeuMnll, for the i)re- 

 vention of which soaking the seed in copper solutions or tlie hot-water treatment is 

 recommended. The leaf scorch of cherries, caused l)y the parasitit: fungus (hiomon'm 

 eri/fhmstomn, is described. Only cherries of the Bigarreau and Heart types were 

 affected. The fungus attacks the leaves, diminishing their vitality, and later some- 

 times attacks the fruit, which i i developed irregularly. Malformed pears, due to 

 attacks of a species of Cladospf)rium, are also brietiy described, and the occurrence of 

 a leaf scorch of orange and lemon trees grown in a hothouse is mentioned. The 

 cause of the leaf scorch is said to be an attack of the fungus Glceonporium henderwnii. 

 The chrysanthemum rust {Puccinia chryscmlhemi) is mentioned and a disease (^f the 

 apple in which the 1 -year-old twigs are attacked by a species of Melanconium is 

 described. A wilt disease of ho])s due to Fusotna j'nrasUicum and an eelworm of hops 

 {Ileterodera .fcliacJdii) are described. 



Plant diseases, G. Massee [Jour. Hoy. Jlort. ^S'oc. lLondon~\, ,^6 (190J), Xo. 4, 

 pp. 7J4-744, .fig-'f- 11)- — This paper consists of a resume of a series of lectures treating 

 of the general conditions regarding jjlant diseases, and gives descriptions of a num- 

 ber of the more common fungus diseases of herbaceous plants, fruit and other trees. 



Ne-w heteroecious rust fungi, H. Klebahn {Ztschr. Pflanzenkrank, 11 {1901), No. 

 4-5, p. 193) . — Brief notes are given upon a number of heteroecious rust fungi in 

 which the alternate hosts are mentioned. The ^Ecidium of Coleosjwrium pidmtdhv is 



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