'IMIK MoXTIir.Y BULLETIN. 183 



presented what I believe to be a .sound reason for saying that no 

 inspector can be absolutely sure to reject all trees affected with the 

 disease. 



WHAT AN INFECTED TREE MAY BE EXPECTED TO DO WHEN SET 



IN THE ORCHARD. 



When an infected tree is planted in the orchard we have no reason 

 to believe that the fungus is going to die out of it wliile sufficient 

 moisture is present to keep the tree alive. We have definite record 

 of trees in Armillaria spots which have become infected during the 

 first season. I seriously doubt whether a healthy, vigorous tree is ever 

 killed during the first season from setting, but such jnight be the case. 

 In subsequent years, however, infected trees will die, some during the 

 second, some during the third and others during subsequent years. 

 The rapidity of the development of the fungus seems to be so imcertain 

 that we can not predict how long an infected tree may live. So far as 

 I know no experiments liave been made in setting out trees known to 

 be infected with Armillaria and observing the length of time which 

 would elapse before their death. Such experiments might be inter- 

 esting, but would seem to be more or les.s unnecessary becau.se we feel 

 confident that such trees will die in the end. 



When a tree dies the troultle has only commenced, because in remov- 

 ing the tree to replant, especially if it has grown for a number of 

 years, there is very small probability that all of the diseased roots 

 will be removed from the eoil. Other roots which probably will be 

 found in most situations lying in the soil from previous tree growth 

 can be expected to become infected with the fungus. Roots of 

 neighboring trees will become infected and a typical Armillaria spot 

 established. 



THE DUTY AND THE OPPORTUNITY FOR THE HORTICULTURAL 

 COMMISSIONER AND INSPECTOR. 



I take it that tlie procedure is clear in regard to infected nursery 

 trees and that these will be condemned wherever they are detected. To 

 my mind the danger lies in those which may escape detection, and it 

 seems to me that all persons who have the fruit interests of the State 

 at heart should use their influence to prevent the use of Armillaria 

 spots for the growing of nursery trees. 



It is not my purpose to discuss the procedure to be adopted where 

 such nurseries are discovered or if a case should arise in which a grower 

 insisted upon using diseased land for nursery. As to Avhether all of 

 the nursery trees found growing in an Armillaria spot should be con- 

 demned remains a rather delicate question. But it seems to me that 

 none of such trees can be used with complete safety, for although 

 not all such trees are infected, some are almost certain to be. If any 

 way were known to us which was absolutely sure to be effective for 

 dealing with a new infection of Armillaria in the orchard, or if such 

 a method should be demonstrated in the future, there might be room 

 for discussion as to whether it might be best to use carefully inspected 

 trees and then deal with the spots if they should appear in the orchard. 

 In view of the actual siturition, it seems that nursery trees from 

 Armillaria spots are exceedingly undesirable. 



3—16579 



