90 STATE HORTICULTURAL SOCIETY. 



Prof Sanders — They do not put any poison into the tree. 

 They have a slight ])eeuliar reddening eflect ujjon Ihe bark of 

 llie tree, bnt where they get in tlieir work is by pnsliing their 

 probosis into the bark and sucking out tlie sap. 



Q. Will the same fumigation for scale destroy root-ai)liis with which 

 many roots are affected? 



Prof. Sanders — A proportion of the root aphis will be killed but some 

 may not be killed. Nor will the eggs of many of our butterfles and 

 moths be killed by the same fumigation. That has been brought out 

 very clearly Avith experiments made for the control of the Gypsy moth 

 This was introduced into our country on foreign stock in the egg stage. 

 Nicotine Solution, kerosene emulsion, whale oil soap are good remedies 

 for plant lice. 



Q. Will dormant spraying kill scurvy bark louse as well as the San 

 Jose scale? 



Prof. Sanders — It will do this to a larger extent than with the oyster 

 scale louse. It is best to spray late in the spring for both. You can 

 sjtray immediately before the leaves unfold, Avhen the buds are swelling. 

 I>ut you can eradicate oyster scale on trees with the kerosene emulsion 

 which is effective against any scale insects. 



Q. Is the crown gall any sufficient reason for rejection of nursery 

 stock ? 



Prof. Sanders — That is another question that is unsettled. That 

 question was largely discussed through the afternoon in the Minnesota 

 meeting and a representative of the Jewel nursery claimed that he 

 had conducted some extensive ex{)eriments in whicli he found that he 

 was in position to declare^ that the crown gall Avas not dangerous 

 lo a tree. I still am on the doubling side and sliall not accept the state- 

 ment as conclusive proof to tliat effect. If the tree is diseased in any 

 Avay, and that is a disease, I Avould prefer not to have it in my nur- 

 sery or orchard. 



Q. Must Ave accept it from the nursery? 



Prof. Sanders — 1 do not believe you have to accept it, at least not 

 under the Wisconsin laAVS and 1 think that most of the state legislatures 

 have enacfed similar laws. 



Q. Do vou faA'or the fall or the spring in Avhich to spray for the 

 scale? 



Prof. Sanders — I would prefer the spring, because you kill the scale 

 and you kill many of your fungus diseases at the same time if 3'ou 

 use lime-sulitliur solution. 



Q. Recently I had to look up the croAvn gall and found the state- 

 ment in the bulletins Avhich came from the department of agriculture 

 and also state Itulletins as Avell that the crown gall Avould not only kill 

 (he tree but it Avould inoculate the ground so that it Avould be im- 

 possible to make another groAV where that croAvn gall tree had stood. 



Prof. Sanders — Statements haA^e been made and repeated in bulletins 

 to that effect and also to the contrary so there seems to be quite a 

 divergence of opinion on the subject. I do not, however, think the 

 croAvn gall of quite the same nature as the peach yelloAvs. We do 

 not knoAv the cause of the latter disease although Dr. Erwin Smith 

 and many others haA^e been Avorking for years and as yet they are un- 

 able to tell just what the cause is. 



