334 [ THE PEACH AND THE NECTARINE 



in shaded situations. Trees growing in very sunny 

 situations may have their foliage discoloured by the 

 action of the sun's rays, but this alteration which is of a 

 purely physico-chemical nature is easily distinguishable 

 from ''yellows" in which the leaf becomes veined or 

 marbled yellow, or entirely pale yellow with some green 

 at the base of the leaf and along the principal nerves, and 

 scions or buds taken from diseased trees should be 

 avoided as they generally produce sickly trees and com- 

 municate the disease to the stock. The diseased foliage 

 is shed early in autumn, and if the disease is in an 

 advanced stage the tree dies. The complaint is cured or 

 at least greatly modified in its incipient stages, by 

 watering the tree with a solution of green vitriol ( ferrous 

 sulphate) towards the close of April or May when the 

 tree is still in active growth, but the soil is already getting 

 dry. However, the use of organic manures, especially if 

 not thoroughly fermented, may cause the disease to take 

 an acute form and to kill the tree in a few weeks. 



The "rosette" is another obscure disease closely 

 allied to chlorosis, and is also supposed to be infective as 

 a bud or scion taken from a diseased tree will not only 

 reproduce sickly plants, but may communicate the disease 

 to a healthy tree if budded or grafted upon it. This 

 disease is rare with us, and is characterized by the pro- 

 duction of small deformed leaves, set close together so as 

 to form a "rosette" at the ends of the twigs and spurs. 

 Trimming back the diseased twigs may bring about some 

 improvement, but the disease is usually incurable. 



The shot-hole fungus of the peach (Cercospora cir- 

 cumscissa Sacc.) is rarely met with on our trees. The 

 lesions produced by this fungus consist in small round 

 whitish spots which dry and break through, leaving round 

 holes. The best treatment against this disease consists 

 in spraying with sulphur-lime mixture. More common is 

 Phyllosticta Persicae Sacc. which produces dark roundish 

 spots with minute darker dots, and enclosed by a red 



