REPORT OF THE APPLE AND PEAR CONFERENCE. 45 



by gun shot, &c, were always liable to produce canker; in healthy 

 trees, however, it made little progress, whilst trees rendered un- 

 healthy through inferior soil or insufficient nourishment quickly 

 succumbed. His advice, therefore, was to carefully protect all 

 bark wounds from atmospheric disease germs. 



Mr. Tones did not believe canker to be due to germs of any 

 sort, nor that wounds of any kind could produce it, although, no 

 doubt, it might be that the disease developed more readily in 

 injured parts. 



Mr. Clark asked how it was that canker attacked one sort 

 and not another, when perhaps there was only a roadway between 

 the different varieties? 



Mr. Tonks : Because the food which one tree wants is quite 

 different to that required by another. Years ago I had a tree of 

 Citron des Cannes which grew excellently and bore well. After 

 a time it showed signs of an attack of canker. I at once budded 

 it with Pitmaston Duchess. In process of time the Citron des 

 Carmes languished and ceased altogether to bear, and became a 

 most miserable object. I then sawed off all but the bough budded. 

 Hitherto the growth of the Pitmaston Duchess had been entirely 

 pendulous, but it now took an upright habit of growth and 

 became laden with fruit, though nothing whatever else had been 

 done, thus proving that roots and soil which could not maintain 

 Citron des Carmes were perfectly able to support Pitmaston 

 Duchess in utmost luxuriance. 



Mr. Clark related how some years ago he took eighteen acres 

 of meadow land and well trenched it, and planted 250 each of 

 Cellini, Wellingtons, Early Juliens, &c. The Wellingtons grew 

 well and prospered, but the Cellini all cankered after bearing 

 for one or two years. He therefore cut off the heads of them 

 all, and grafted the stems with Manks' Codlin, which at once 

 started well, had no sign of canker, and bore well. The canker 

 even disappeared from the stems. The Early Juliens were 

 almost as bad as Cellini. So that it would appear as if canker 

 attacked certain sorts, but was not in the soil, and the only cure 

 for it was to cut clean out all the wood and every particle of bark 

 that was suffering from it. 



Mr. George Bunyard thought that the effect of frost in 

 producing canker had been overlooked. There were some sorts 

 of apples did well and were in great request in Kent up till the 

 severe frost of 1881, since which time the market growers had 

 entirely given them up because they had cankered so badly. 

 When the frost comes in spring, just as the sap is rising and 

 the bark swelling, it is specially liable to cause canker. He 

 knew of an orchard of young Cellini producing magnificent 

 crops, but in 1882 they were all cankered, which he believed 

 was all due to the frost, for the ground was an old hop garden 

 which had been for years well manured. He had often noticed 



