APPENDIX. 337 



gether from nursery stock is at once apparent, and this Mr. Stedman has 

 shown to be possible by placing tobacco dust freely in the trenches in which 

 the seedling's or grafts are planted and in the orchard excavations for young 

 trees. Nursery stock may be continuously protected by laying each spring 

 a line of the dust in a small furrow on either side of the row and as close 

 as possible to the tree, covering loosely with earth. For large trees, both 

 for protection and the destruction of existing aphides, from two to five 

 pounds of the duet should be distributed from the crown outward to a dis- 

 tance of two feet, first removing the surface soil to a depth of from four to 

 six inches. The tobacco kills the aphides by leaching through the soil, and 

 acts as a bar for a year or so to reinfestatiou. The dust is a waste product 

 of tobacco factories and costs about one cent per pound, and possesses the ad- 

 ditional value of being worth fully its cost as a fertilizer. 



The use of bi.-iiilphide of carbon for the woolly aphis is the same as for the 

 grape root-louse. It should be applied in two or three holes about the tree to 

 a depth of six to twelve inches and not closer than one and one-half feet to 

 the crown. An ounce of the chemical should be introduced into each hole, 

 which should be immediately closed. The bisulphide evaporates and pene- 

 trates throughout the soil and readily and promptly kills the aphides. It 

 does not, however, furniah any protection from future attacks, and it is 

 attended with danger to the tree unless the precautions named are carefully 

 observed. That it is highly inflammable should also be constantly borne in 

 mind. If it is to be used at all extensively, an automatic injecting device 

 should be secured, such as the McGowan injector. The chemical costs ten 

 cents per pound in fifty- pound cans of the manufacturer, E. R. Taylor. 

 Cleveland, Ohio. 



Badly infested nursery stock should be destroyed, since it would be worth 

 little even with the aphides removed. Slightly infested stock can easily be 

 freed of the aphides at the time of its removal from the nursery rows. The 

 soil should be dislodged and the roots pruned, and in batches of a dozen or 

 so the roots and lower portion of the trunk should be immersed for a few 

 seconds in water kept at a temperatnre of 130° to 150° P. A strong soap 

 solution similarly heated or a fifteen times diluted kerosene emulsion will 

 give somewhat greater penetration and be more effective, although the 

 water alone at the temperature named should destroy the lice. This treat- 

 ment is so simple and inexpensive that it should always be insisted upon by 

 the purchaser if there be any indication of the presence of this insect, and 

 stock exhibiting much damage should be refused altogether. 



After planting, if the trees be kept in vigorous growing condition by 

 careful cultivation and, if necessary, proper fertilizing damage from the lice 

 is much less apt to occur, and the principal danger period, namely, the first 

 two or three years after planting in the orchard, will pass in safety. The 

 value, as a means of protection, of thorough cultivation and good care of 

 young orchards can not be too strongly insisted upon. Vigorous growing 

 trees have a decided power of resistance or are able to sustain with com- 

 paratively little damage the presence of the root-lice, while ill-cultivated 

 and neglected orchards are especially liable to injury. 

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