440 



Agricultural Gazette of N.S.W. 



[June 2, 1920. 



lo<?ged bark. The spores which propagate the fungus can be washed down 

 irrigation channels from previously infected trees, and can be carried on to 

 the land in small amounts of soil. They may be adhering to nursery stock 

 or soil, and in some cases are carried fi'om tree to tree by the grower on 

 implements. This can happen especially in treating diseased trees if care Is 

 not observed with the knife. In some cases tiny white tufts — the s^wres of 

 the fungus — can be observed on diseased bark, but may not be very obvious. 

 The fungus parasite grows very slowly through the tissues of the trunk, 

 and slowly, too, accomplishes the ringbarking of the tree if left unchecked. 

 Sometimes a tree will set a fairly heavy crop before death. The decay 

 proceeds upwards to the stem and downwards to the roots. 



Diseased trunk, showing' bark removed fiom 

 vr i-fji; — ^^^^ L*flected area. 



A diseased tree, unhealthy bark removed ; 

 bluestone paste applied. 



The " union " of the tree is sometimes a point of entry, and so should be 

 kept well above gi-ound. Care should be taken to avoid injury to the bark 

 of trees, especially with shovels and hoes when removing weeds. It has to be 

 remembered that the condition is favoured and developed by bad drainage, 

 while moistness of the soil in immediate contact with the trunk is also 

 undesirable. Under iiTigation conditions it is never necessary to run water 

 right up to the tree trunks, and this should be avoided. 



Treatment. 



Where "gumming" is observed the earth should be scraped away from the 

 base of the tree and the whole of the dried bark apparently infected by the 

 fungus should be cut away with a pruning knife, and the wound painted 

 over completely with bluestone paste. 



