117 



of control. On the other hand, to prevent 

 infection by the application of some sub- 

 stances which forms a protective covering 

 is common practice against some diseases 

 and often sound, clean fruit cannot be 

 obtained unless such preventive measures 

 are taken. A fluid used in this way must 

 be applied by some form of apparatus 

 producing a fine mist-like spray which 

 penetrates to all parts of the tree, and is 



Fig. 1. — Young Apples affected by Scab. 



deposited in minute drops, which on dry- 

 ing leave a more or less continuous cover- 

 ing of a fungicidal substance. 



III. — Fungicides. 

 There are two fungicidal spray fluids 

 with which all frviit growers should be 

 familiar, viz., Bordeaux Mixture and 

 ,limc-sulphur. The former is a good pro- 

 tective wash against black spot or scab 

 of apples and pears ; the formula recom- 

 mended for its use on fruit trees is 

 8:8:100, i.e., 8lbs. copper sulphate and 

 81bs. quicklime to 100 gallons of water. 

 The best way of preparing the mixture is 

 as follows : — 



(1) Dissolve 81bs. of copper sulphate in 

 8 gals, of water. 



(2) Place 81bs. of freshly burnt quick- 

 lime in a wooden vessel, and slowly 

 slake by adding a little water from 

 time to time until the lime breaks up 

 to form a thick paste, then add more 

 water to make up to 8 gals, of " milk 

 of lime." 



(3) Eun off 84 gals, of water into a barrel 

 or galvanized iron tank, add the 8 gals, 

 of milk of lime, passing it through a 

 strainer to remove the coarser par- 

 ticles, then add slowly, stirring mean- 

 while, the 8 gals, of copper sulphate 

 solution. 

 The mixture should be used within 24 

 hours of its preparation. The " milk of 

 lime " and the copper sulphate solution 

 remain unchanged however until they are 

 mixed together, and so may be prepared 

 in larger quantities as " Stock Solu- 

 tions " ; the Bordeaux Mixture may then 

 be made as required. 



Lime Sulphur is sold as a concentrated 

 solution which only requires to be diluted 

 with water. The most reliablte brands 

 are prepared of a specific gravity of 1.3 ; 

 one gallon of the concentrate when diluted 

 with 14 gallons of water (giving a S.G. of 

 1.02) forms a useful winter wash for 

 cleansing fruit trees from moss and lichen. 

 For spraying the foliage in summer 1 gal- 

 lon to 29 gallons of water (S.G. 1.01) may 

 be used on some trees, but often further 

 dilution is necessary or scorching of the 

 leaves and fruit will result. 



IV. — Diseases. 

 "Black Spot" oe "Scab" of Apples 



AND Peaes. 

 One of the most troublesome pests of 

 the fruit grower is the fungus Venturia 

 Pomi ( = Fusicladium dendriticum) which 

 causes the diseases known as "Apple 

 Scab." Black or brownish spots appear 

 on the fruit, often while it is still quite 

 small; these spots develop into circular 

 scab-like areas up to about J-inch in 

 diameter, or large irregular scabs are 

 formed when two or more spots coalesce. 

 Not only is the fruit seriously disfigured, 

 but when it is attacked when very young 

 and rapidly increasing in size, growth is 

 retarded on the affected side thus produc- 

 ing a malformed fruit (Fig. 1). If the 

 apples become infected at a later stage in 

 their growth they may develop normally 

 except for the appearance of the black 

 spots which diminish their market value. 

 If scabbed apples are stored a rot of the 

 fruit may occur, caused not by the scab 

 fungus itself, but by other forms which 

 are able to enter at those places where the 

 skin has been ruptured at the scabs. 



