PROCEEDINGS OF THE CANADIAN INSTITUTE. 127 



Interior Therapy : A Case of Leaf-Curl. Bv Arthur Harv^ey, Esq. 



{Read 2 1st November, igoj.) 



I HAVE always had trouble v/Ith peach-trees owiag to their liability to " leaf- 

 curl." I am not aware that it is annoying to larger growers, or on other than 

 clay land. Bat in Rosedale I have found more than half my trees affected by it. 

 It is destructive to the crop. I suppose it to be a bacterial disease. 



As soon as the leaves are an incli or two long, their substance thickens about 

 and around the point attacked, the swelling soon deforms them, a sort of knot is 

 formed, they curl, turn red and yellow in places, and as most of the leaves ai'e 

 thus affected, the branches look as if blasted by some irritant poison. If left to 

 themselves, the diseased leaves will fall off, others will grow further up the shoots, 

 but even they are liable to be affected, though not to the same extent. If picked 

 oft', which with smiU trees I have tried to do completely, the same result follows ; 

 the disease is not conquered even by two years of such drastic treatment. Some 

 trees have this " leaf curl" worse than others, some are quite immune. 



Last year a fine Elberta in my garden was beginning to blossom, and it suf- 

 fered so much that I would have cut it down had I not wished to attempt a cure. 

 This spriag, as soon as the evil began to show itself, I bored a gimblet hole in one 

 of the branches, at an angle of 45° with the horizontal. Into this I fitted a quill, 

 and kept the quill full of a saturated solution of copperas. The tree absorbed a 

 quillful in about six hours. In a day, I could see that the leaves in the upper 

 part of the branch were affected, and those which wilted in this manner soon died, 

 and no farther vegetation took place to supply the want of them. I soon perceived 

 that the copperas had not been diffused to any appi'eciable extent, for the injury 

 went along one only of the branches springing from that which was under treat- 

 ment, and only one of the final tufts of leaves was killed. The particular fibres 

 cut by the gimblet had soakei up the solution, which did not extend to others 

 but only to their own continuations. This, I believe, puts an end to all hope of 

 success in the particular direction attempted. A weaker solution, or one of a 

 difterent kind, would in like manner affect a few fibres only and their 

 ramifications. 



In the fall there was a line of spots, exuding gum, along the whole of the 

 affected fibres, not elsewhere, except that below the boring there were also a few, 

 due to the death of the fibre leading upwards from the root, from want of exercise. 

 Not having any connecting tubes, it got choked. The rest of the tree was not 

 affected by the copperas, it suffered as usual from " leaf curl," and I shall cut it 

 down next spring. 



I may say that washing the bark with lye or the usual poisons has no pallia- 

 tive effect, in my experience. 



