96 FRUIT TREES AND THEIR ENEMIES 



or \\ ozs. of potassium cyanide, to every i,ooo cubic 

 feet of air space. 



Powdery Mildeiv {UncinuJa spiralis). — The summer 

 form of this fungus is alone met with in England. It 

 forms white patches on the upper surface of the 

 leaves in spring, and gradually spreads over the whole 

 leaf, and attacks the fruit as well. 



Remedies. — As soon as ever the disease is noticed, 

 the vine should be sprayed with potassium sulphide, 

 I oz. to 3 gallons. A second application should be 

 given when the vines are in full bloom, and a third 

 may be given three or four weeks later. 



Fruit Trees in General 



Bii'ds. — Although the good done to the fruit 

 grower by birds in destroying insects is unquestion- 

 able, it is equally beyond doubt that he suffers severely 

 from them, both through their depredations on ripe 

 fruit, and through their destroying the blossom-buds 

 and blossoms. The damage done to ripe fruit is an 

 evil with which the grower has always had to contend, 

 as also is the destruction of the buds of goose- 

 berries and red currants, and a limited damage to 

 blossoms by sparrows, chaffinches, linnets, etc. : but 

 the destruction of the buds of plums, pears, and even 

 apples, has increased very much of late years, and is 

 proving to be little short of a disaster to many small 

 growers. Plum trees may sometimes be seen which 

 have been stripped of every bud, and look like dead 

 trees in spring, whilst plantations which were formerly 

 •profitable, have had to be grubbed up, owing to the 



