140 BOARD OF AGRICULTURE. [Jan., 



entire tree is cut and burned instead of the small portion which 

 is visibly affected, as in the case of the black knot. In treating 

 apple canker, badly diseased or dying branches may be cut 

 back to healthy wood and grafted at once with scions of the 

 same variety. In this way the larger wounds which are neces- 

 sarily made in cutting out the diseased parts may be healed 

 most rapidly. Spraying with fungicides probably has some 

 effect in reducing the amount of the disease. Washing the 

 trunks and branches with a mixture of lime, wood ashes, soap, 

 and copper sulphate has been tried, and recommended by some. 

 The value of such washes has not yet been satisfactorily de- 

 termined. 



The treatment for some injurious insects may be combined 

 with the treatment for fungous diseases, thus saving the 

 expense of separate applications of the fungicide and the in- 

 secticide. Since Prof. Britton is to present the subject of in- 

 sects in their relation to agriculture this evening, we will con- 

 -sider at this time only those injurious insects which may be 

 fought by these combination treatments. Paris green or some 

 equivalent arsenical poison may be used against the potato 

 beetle in combination with the Bordeaux mixture when that is 

 being applied for potato blights. This treatment also, to a 

 large extent, prevents the attacks of flea beetles, which it ac- 

 complishes, not by poisoning the flea beetle, but by rendering 

 the foliage distasteful to them. 



In spraying currants with an arsenical poison to destroy the 

 saw-fly larvae, commonly called currant worms, Bordeaux 

 mixture may be applied at the same time for leaf spot and 

 anthracnose. In fighting the grape-vine flea beetle the first 

 treatment with the arsenical poison is made in spring just be- 

 fore the buds begin to swell. You will remember that formerly 

 hellebore was quite largely used in fighting currant worms, 

 but those who are growing currants largely now are coming to 

 use paris green, or some arsenical compound, spraying the 

 plants before the fruit becomes large enough to be spotted 

 by the spray. It is very effectual and more satisfactory. 



Bordeaux mixture may be used at the same time for the 

 grape anthracnose; and succeeding treatments, after the foli- 

 age appears, may be made with the arsenical poison, when the 

 Bordeaux mixture is used against the grape mildews and the 

 black rot. 



