58 The Canadian Horticulturist. 



DISEASES OF RASPBERRIES AND BLACKBERRIES. 



^HE red rust is comparatively well understood since the Department of 

 Agriculture has investigated it. This rust has a perennial mycelium 

 which lives over winter in the plant and develops with the young 

 canes the following spring. In the summer of 1892, a single black- 

 berry-bush was found on the station-grounds, affected with the disease. 

 On June 23rd all the canes were cut close to the ground, and new 

 ones, apparently healthy, sprang up. This spring, however, at the 

 usual season, the leaves and twigs were covered with the well-known orange-red 

 color, showing that the fungus had been continuing its growth all the time within 

 the tissues of the plant, and was ready to develop its spores at the proper time. 

 This one fact in the life-history of the fungus being known, it is easy to see that 

 a plant once attacked is doomed, and that the only remedy is to dig it up and 

 burn it. Spraying may prevent the germination of some of the spores which it 

 scatters abroad, but it is far cheaper to begin at the source and prevent their 

 production in the first place, by rooting out and burning every diseased plant 

 the moment it is discovered. It may be necessary to look after the wild 

 raspberry, blackberry and dewberry plants in the vicinity, for, if they are 

 numerous and badly affected, the disease may spread from them faster than from 

 any other source. 



The anthracnose, gla^osporium venetum, is another serious disease. The 

 hyphae of this fungus do not extend from the old to the new canes, as in the red 

 rust, and if all the portions could be cut away this would be an effective remedy. 

 The attacks of the fungus, however, are so indiscriminate and general that in 

 most cases the remedy is impracticable. It is hard to counteract it by spraying, 

 because of the difficulty in protecting all portions of the cane with a coating of 

 the material. Probably the Bordeaux mixture will be found effective if the 

 spraying is begun with young plantations, and the treatment continued throughout 

 the year. 



Another disease, which is probably more common than is generally known, 

 manifests itself by large knotty swellings of the roots. Affected plants lose their 

 vigor and productiveness, and with our present knowledge, we can only say, that 

 it will be prudent to avoid setting out plants which show any such swollen roots. 

 The cause of these swellings is yet a mystery.— Garden and Forest. 



'■ That Fruit Growing in Ontario is so extended an industry seems to be 

 a great surprise to our American cousins. We notice in the N. Y. Commercial 

 Bulletin and in the California Fruit Grower, a paragraph quoting Prof. James' 

 statement at our Peterboro' meeting, that the Province of Ontario has 7,000 

 bearing apple trees, 2,000,000 grapevines, 700,000 plum trees, and 500,000 each 

 of cherry, pear and peach trees. 



