776 EXPERIMENT STATION RECORD. 



Die-back of the apple, D. McAlpine {Jour. Dept. Agr. Victoria, 1 {1902), No. 6, 

 p y,j7). — The attention of the author has been called to a disease of apple trees 

 known as die-back. Subseciuent investigations have shown that in numerous cases 

 the trees were attacked by an agaric {Armillaria mellea) . The abundant presence of 

 this mushroom has led to the conviction that it is the cause of the disease locally 

 known as die-back. 



Brown rot or ripe rot of fruit, D. McAlpine {Jour. Dept. Agr. Victoria, 1 {1902), 

 No. 7, pp. 701, 702, pi. 1) . — The effect of attacks of Monilia fructigena upon different 

 fruits is shown, and for the prevention of the disease spraying Avith Bordeaux mix- 

 ture is recommended. All diseased fruit should be collected and burned to prevent 

 the spreading of the fungus spores. 



Peach and plum rust, D. McAlpine {Jour. Dept. Agr. Victoria, 1 {1902), No. 6, pp. 

 617-G19, pl^. 2). — A descriiition is given of the peach and plum rust {Pucdniapruni) 

 in which the most susceptible varieties of host plants are mentioned and the applica- 

 tion of Bordeaux mixture for its prevention is recommended. 



Clasterosporium carpophilum and its relation to the gummosis of stone 

 fruits, R. Aderiiold {Arb. K. Gesundheltsamte, Biol. Abt., 2 {1902), No. 5, pp. 

 515-559, j)ls. 2, figs. 6). — A description is given of the various forms of disease pro- 

 duced by Clasterosporium on stone fruit trees, and a detailed characterization of the 

 fungus when grown in natural and artificial media is given. An historical statement 

 regarding the fungus is presented, together with its synonymy and morphology, also 

 the results of inoculation experiments. The relation of this fungus to the so-called 

 gummosis or gum flow of stone fruits is discussed, and the conclusion is drawn from 

 inoculation experiments that the Clasterosporium was the cause of the appearance 

 of gum in all the experiments, and that the general conclusion is warranted that 

 this fungus is a prominent cause of gum flow from wounds on stone fruit trees. A 

 brief bibliography accompanies the paper. 



Variations in the appendages of Podosphaera oxycanthse, J. G. Sanders 

 {Jour. Mycol., 8 {1902), No. 64, p. 170, fig. 1). — A brief note is given of variations in 

 the appendages of the cherry powdery mildew, in which the branching of the 

 majority of the appendages was noted. 



A disease of pineapples {Agr. Nevis \_Barhados], 1 {1902), No. 14, p. 213). — A 

 brief account is given of a disease of pineapple plants in which the younger stages of 

 the disease are characterized by the tips of the leaves turning yellow and drying up. 

 As the disease progresses the discoloration of the I'^aves proceeds further until they 

 are more or less wilted. The symptoms pointed to an insufticient water supply, and 

 an examination of the roots showed in many cases that they were blackened and 

 rotten. There was an unusual development of root hairs on the old roots, and the 

 root hairs showed the presence of the threads of a fungus. It is believed that the 

 extraordinary development of root hairs was caused by special effort on the part of 

 the plant to replace those destroyed by the fungus. It is suggested that wherever 

 this disease occurs all affected plants should be dug up and burned and the soil thor- 

 oughly limed. 



On the occurrence and characteristics of black rot in Dagestan, N. N. von 

 Speschnew {Ztschr. Pflanzenkrank., 12 {1902), No. 1-2, p. 10). — The occurrence of 

 black rot of grapes is reported in which the characters of the disease resem])le those 

 of. the ordinary black rot to a considerable extent, but the fungus causing the disease 

 is said to be Diplodia uvicola, instead of the usual Guignardia hklwellH and G. reniformis. 



An experiment on the treatment of gray rot of grapes, F. Boisseau {Prog. 

 Agr. ct Vit. {Ed. L'.Est), 23 {1902), No. 47, pp. 601-603).— K brief account is given 

 of spraying experiments in which fungicides containing potassium permanganate, 

 alum, copper sulphate, and sulphur were tested. The best results were obtained 

 with the alum fungicide, followed by that in which potassium permanganate at the 

 rate of 125 gm. per hectoliter of water was used. 



