April, '10] INSPECTORS' DISCUSSION 249 



vague hypotheses as to the methods by which he can eradicate that 

 disease. 



S. J. Hunter: It seems to me that we have arrived at a place 

 where we may properly ask the question : What part can this Associa- 

 tion take in dealing wdth such cases as the one under consideration? 

 It would seem pertinent to ask, Can this Association standardize the 

 work of the inspectors in the various states 1 It is generally conceded 

 that the Crown GaU may be found wherever apple stock is grown. 

 The gentleman from Iowa has given proper expression to this phase 

 of the subject. There is some difference of opinion regarding the in- 

 jurious effect of this crown gall, but the majority, I believe, look upon 

 it as highly detrimental to the life of the host. Crown Gall in the 

 more advanced stages is more readily recognized and therefore does 

 not pass as readily as some of the subjects of quarantine. The issu- 

 vance of a certificate, with the understanding that the recipient will cull 

 -out all the Crown Gall, is a common practice, although by no means a 

 satisfactory one. It seems to me that it is time for us to consider in- 

 spection both at the nurserj^ grounds and at the point of destination. 



Mr. J. L. Phillips : We have done a great deal of work on Crown 

 GaU for five or six years, and we have found, almost invariably, that 

 trees affected by Crown Gall may grow fairly well in the orchard dur- 

 ing the first year or two, but will die before many years. They 

 simply rot off and die. The nurserymen have had a great deal of 

 trouble of late years, as some trees in consignments are found to have 

 Crown Gall, while the majority are all right, and we do not feel like 

 discarding them, unless absolutely necessary. 



We realize, also, that this is one of the most serious troubles with 

 which the nurseryman has to deal, and we have given a good deal of 

 thought to it, and conducted many experiments. 



We noticed that scions from trees affected with Crown Gall would 

 produce diseased trees. Forty to 60 per cent of our experimental trees 

 were affected by this disease where scions were cut from diseased trees. 



If you get scions from healthy trees, you will have little or no trou- 

 ble. We had an opportunity to make observation during the past two 

 years in quite a large number of trees in a new nursery'. 



The scions came principally from old orchards. A large percentage 

 of the trees are in the nursery at the present time, but of those taken 

 out last fall only about from 6 to 9 per cent were affected with Crown 

 Gall. 



Our present understanding of the matter is that scions cut from 

 trees diseased with crown gall will transmit the infection into trees 



