62 



and burned, and thus utterly destroyed, the better it will be for the peach 

 industry. 



I have now described the disease in its worst form, a form in which it is 

 not uncommon. The milder forms of the disease are much more frequent. 

 Sometimes only part of the leaves on the tree are attacked, or the leaves are 

 only partially attacked and display the curl in one-half only, or at the end, 

 or elsewhere. These appearances, however, are so similar to those already 

 described that there can be no mistaking them. The curl is there ; the dis- 

 tortion, the discolouration, the thickening, the lividness, are all present and 

 unmistakable. There is, however, a masked form of the disease which 

 usually escapes notice even under the eye of the expert. It may be known 

 "by the leaves having a slight tendency to overgrowth and a slight tendency 

 to crimple. There is no deformity in this form of the disease ; the leaves 

 are well formed, only somewhat darker green than usual and slightly over- 

 grown. Trees attacked thus often bear fairly well, and it may therefore be 

 asked whether this form is worth notice. I think it is worth notice for this 

 reason : Leaf-curl is a disease that varies from season to season ; some seasons it 

 is almost absent except on trees in which it is chronic and severe, and other 

 seasons it is very common, widespread, and injurious. In seasons when 

 the diseass is very prevalent those trees which in ordinary seasons show 

 the disease only in its masked form break out badly and bear little or no 

 fruit. 



The description of this disease would be very incomplete without making 

 plain mention of the fact that the fungus described above as occurring on the 

 leaves may be traced from the leaves back to the wood. That is an impor- 

 tant fact, because it leads to the conclusion that the disease is one that 

 -cannot be got completely rid of by any treatment of the leaves by spraying 

 with fungicides. The fungus will winter in the wood, and be ready to 

 make the most of its opportunities in the spring. 



Remedies and Preventives. 



1. Foremost in rank among the various methods of treatment which I 

 ^advise is care in grafting and budding. This disease can exist in the wood 

 even when the leaves show only slight traces of it. As already described, 

 the diseased leaves of early spring are usually followed by fairly healthy- 

 looking summer leaves, so that except for a dearth of fruit (and even that 

 may not be great) the tree may look quite fit to take scions from. Along 

 comes the nurseryman or orchardist, bent on increasing his stock of trees, 

 takes a look at this tree, and seeing nothing much the matter, proceeds 

 to remove scions and graft them wholesale on fresh stocks. There can be 

 'but one result diseased trees. I am confident that this is the manner in 

 which the disease is commonly spread from one place to another at a distance. 

 Orchardists, therefore, who have an eye to the future, and nurserymen who 



care anything for their reputation, will refrain from grafting or budding from 

 trees that have this disease. Grafting and budding should be done only 

 from peach-trees that have either never shown the slightest traces of curl, or 

 .from such as have been entirely free from it for at least two seasons. 



2. Almost equal in importance with the foregoing is the selection of curl- 

 resistant varieties. It is a well-established fact that some varieties of peach 

 resist the leaf -curl, and are but slightly injured by it, while others seem to 

 be quite proof against it. I am sorry to say that no list of the resistant 

 varieties has been obtained for Australia, so that we are completely in the 



