332 The Spraying of Plants. 



Treatment. It is probable that the disease can be checked 

 by spraying the trees with the Bordeaux mixture as soon as the 

 fruit has set, and following this at intervals of two weeks by 

 two treatments of one ounce of the carbonate of copper dissolved 

 in ammonia and diluted with twelve gallons of water. 



Rosette. This disease causes the growth of affected trees to 

 become compressed and bunched in the form of a rosette. The 

 causes as well as the remedies are unknown. The disease is 

 found only in the southern states. It is contagious, and affected 

 trees should be destroyed. 



Yellows. Peach yellows is a disease which has so far baffled 

 all researches as to its cause or the methods of curing affected 

 trees. The trees first ripen their fruit prematurely, the peaches 

 possessing distinct red streaks extending from the surface towards 

 the pit. The following years the new growth is generally tufted, 

 and branched shoots are produced from wood that is more than 

 two years old. Such growths have narrow, horizontal leaves, 

 which are yellowish in color. The disease is contagious, and 

 affected trees should be burned as soon as the disease is dis- 

 covered. No cure is known. 



INSECT ENEMIES. 



Black Peach-aphis (Aphis Persicce-niger, Smith). Descrip- 

 tion. These plant lice are shining black in color, one form hav- 

 ing wings, the other possessing none. They feed upon the juices 

 of the trees, and may be found upon the leaves, stems, and roots. 

 They reproduce in the characteristic manner of plant lice. 



Treatment. The insects found above ground may be de- 

 stroyed by kerosene emulsion diluted fifteen or twenty times, or 

 by tobacco water. Those found upon the roots are more diffi- 

 cult to destroy. Tobacco stems or dust may be dug about the 

 affected parts; or the roots may be exposed, and water having 

 a temperature of 130 F. poured upon them. Another remedy 

 which should give excellent results is to inject bisulphide of 

 carbon about the roots, using about a teaspoonful to every 

 square foot of soil. The roots of young trees may be dipped 

 in hot water or in kerosene emulsion before setting them in 

 their permanent positions. 



Borers. See under APPLE. 



Plum Curculio. See under PLUM. 



