SUMMER MEETING. 27 



In the case of apple seedlings and common apple nursery stock I 

 should not advise the use of carbon bisulphide. Unless extremely 

 cautious, there is too much danger of killing the trees. In these cases 

 the young trees can be kept free from the wooly-aphis by the liberal 

 use of finely powdered tobacco. Small trenches should be dug and 

 filled with a liberal supply of the tobacco dust covered with a little 

 earth, and the seedlings grown in these. In planting nursery apple 

 grafts, buds, or small trees, farrows should also be dug and filled with 

 a liberal supply of the tobacco dust covered over with a small quantity 

 of earth, and the plants set in these. Then every spring, just as settled 

 warm weather appears, the young trees should be treated again by 

 making a furrow along each side of the rows close to the tree — say two 

 inches — filling this with the tobacco dust and covering it over. Two 

 boys, one to make the farrow, which can be done with a hoe nearly as 

 fast as one can walk, and to cover it after the second boy has filled it 

 with tobacco dust, will apply this material to several acres of nursery 

 stock per day. 



The tobacco dust will leach down with every rain and more or less 

 saturate the earth about the apple tree with nicotine, which will not 

 only kill every aphis that may be there, but will prevent others from 

 entering, and at the same time act as a strong fertilizer to the tree. 

 Tobacco dust is worth what it now costs — one cent per pound — as a 

 fertilizer, and is worth much more as an insecticide against the wooly- 

 aphis. The Station is indebted to the Olden Nursery Company through 

 the kindness of Mr. S. R. Hammond, who not only placed a badly in- 

 fested field of nursery stock at our disposal, but who also greatly as- 

 sisted US in the experiments. 



Since the wooly-aphis damages nursery stock and causes a finan- 

 cial loss principally from the fact that the young trees that are badly 

 infested have distorted, swollen and knotty roots, and are not mer- 

 chantable, it is far better to prevent the aphis from ever attacking the 

 trees than it is to kill them after they have caused this characteristic 

 condition of the roots, for the real damage is then done and cannot be 

 cured. If the trees that are being sold or put in cold storage are in- 

 fested in the least — and this can be detected not only by the character 

 of the roots, but also by the presence of the bluish-white downy or 

 cottony matter — the roots should at once be cleaned by shaking and 

 then thoroughly dipped for a minute in strong kerosene emulsion. 

 This will kill the aphids; and it should be practiced not only by every 

 nurseryman, but also by every person setting out apple orchards, even 

 though the trees may have been so treated by the nurseryman. 



