60 Vict. Provincial Boaed op Horticulture. 49 



(2.) It has long been observed, that with many crops certain varieties are more liable to 

 fungous diseases than others. The reason for this, in many cases, is not well understood, but 

 . the fact will lead the careful cultivator to select such varieties as prove most 



Resistant '"^si^'^*"* ^^ '"s locality. Injurious fungi may be largely destroyed by keep- 

 Varieties. i'^S farm and orchard premises clean and free from weeds and rubbish. 

 Burning potato tops, old tomato vines, and similar refuse, will destroy millions 

 of spores of fungi attacking those plants. The same may be said of apples and pears infected 

 with scab of the fruit, which are too often left hanging on the trees or lying on the ground, to 

 propagate their spores the following season. 



(3.) With diseases like the brown-rot of plums and cherries, much may be done in 



H rl P" f reducing injury by persistent hand picking of infected fruit, which should be 



burned. 



(4.) The most practicable way of preventing the majority of the fungous diseases of plants, 



is by the use of " fungicides " or fungus killing mixtures. These act either by directly 



destroying any fungus spores present at the time of application, or by 



Use of remaining on the surface, in a -condition to destroy, either before germination 



° ■ or during that process, any spores that may alight upon the plant treated. 



As treatment is preventive, great care must be exercised to have the work done at the proper 



season, and to be sure that all parts of trees or. plants sprayed are wetted with the fungicide 



used. Drenching is not necessary, and sometimes results in injuiy to the foliage or fruit. 



The aim should be to deposit a thin film or coating of the spray upon the entire surface treated. 



To accomplish this, the Vermorel nozzle should be used to distribute the spray used. 



APPLP: scab or black spot of the fruit ( Fusidadium dendriticum). 



Reported from all parts of the Lower Province, causing great loss to fruit-growers by 

 rendering the fruit useless or unsaleable. 



There is probably no fungous disease of fruit so familiar as the apple scab or black spot 



of the fruit. The fungus which produces the well-known black spots or scabs on the fruit 



also attacks the leaves and young shoots. It first appears on the leaves in 



Apple scab. the shape of smoky, greenish spots, more or less circular in outline. These 



gradually enlarge and run together, so as to form good sized blotches ; as 



they grow older the colour darkens, finally becoming almost black. The young fruit is attacked 



almost as soon as formed, and sometimes shrivels up and drops off. 



The spores or reproductive bodies of the fungus are produced in immense numbers on the 

 blackened spots on the leaf and fruit, forming most abundantly during cool, wet weather. 

 They are disseminated by the wind, etc., and when they light upon a moist leaf or fruit they 

 germinate, sending out a little tube or root, and thus form a new centre of disease. The 

 spores pass the winter on the bark, twigs, and stored fruit, as well as on the fallen leaves and 

 fruit. The mycelium or vegetative portion of the scab fungus develops just beneath the skin 

 of the leaf or fruit, but as a rule does not penetrate deeply into the tissues. After a while it 

 pushes outwards, rupturing the skin and developing fresh spores. 



