1632 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



there are other disinfectants which may 

 he used, bichloride of mercury is far the 

 cheapest, and there is nothing gained 

 hy using anything else. The nse of kero- 

 sene, gasoline and such like is certainly 

 not permissible. Even carbolic acid is 

 distinctly inferior to corrosive sublimate, 

 and besides, its noxious smell and burn- 

 ing tendency do not warrant its use. It 

 must be remembered, however, that cor- 

 rosive sublimate is a deadly poison when 

 taken internally, and the bottle or con- 

 tainer should be plainly marked poi&on 

 Applied externally to wounds, or upon 

 the hands, it will cause no injury, but, on 

 the other hand, will as readily disinfect, 

 as in the case of the tools and cut limbs. 

 The greatest care should be taken in 

 emptying the bottles containing the solu- 

 tion when returning to the house, or 

 otherwise keeping both the bottle and 

 solution away from children or unsus^ 

 pecting persons. As indicated before, 

 there is no danger in getting the solution 

 on the hands; in fact, a cut or wound 

 may be treated with it to prevent bac- 

 terial infection which might result in 

 blood poisoning. It should be understood, 

 however, that the bacteria of pear blight 

 are not pathogenic to man; that is to 

 say, the germ can produce no evil effects 

 even if introduced into the human sys- 

 tem. It is a good plan to use a sponge, 

 which, if fastened by a string about two 

 feet in length and tied to one's clothing, 

 is always handy when it is necessary to 

 •wipe the pruning tools and the cut sur- 

 faces of trees. Some operators tie the 

 sponge by a very short string to the 

 wrist, and this is probably the most con- 

 venient way to use it. An inch or three- 

 quarter-inch carpenter's gouge is also an 

 excellent tool in the makeup of a work- 

 er's outfit With it a small chip may be 

 taken out of the rough bark in inspecting 

 large trees, and, besides, it is a very 

 handy tool in working the blight out of 

 difficult places where ordinary tools 

 cannot be so easily used. In inspecting 

 large trees, whether apple or pear, the 

 gouge must be used to examine the bodies 

 and the crowns. Unless this is done, 

 cases of hold-over will certainly be 



missed. In large, rough-barked trees a 

 chip should be taken out at intervals of 

 about two inches all around the crown, 

 as well as higher up on the body. It is 

 not necessary to go below the outer layer 

 of soft bark tissue, and it is quite un- 

 necessary to cut as far as the wood. 

 When the chip is taken out, if the bark 

 tissue presents a water-soaked appear- 

 ance, or if it is of a red or perhaps bright 

 red color, it is almost certain that the 

 body is infected. When a point of infec- 

 tion is found, it should be followed up so 

 as to determine the extent to which the 

 infection has run. If careful work of 

 this kind is done, no hold-over will escape 

 detection. 



It is a good plan when ignorant 

 pruners are in the orchard to make them 

 disinfect in the general pruning. As a 

 rule, I would suggest that eradication of 

 blight precede the general pruning. A 

 special set of skilled help should do this 

 work, then the ordinary pruner may fol- 

 low. Even in ordinary pruning it is 

 a safe plan to disinfect when leaving 

 each tree in order to avoid carrying the 

 disease in case the pruner has cut into 

 an overlooked case of the blight. There 

 is a question as to what to do when the 

 blight is found running down the bodies 

 and into the roots of the trees. Where 

 the disease occurs on limbs it can be 

 readily sawed off, as the removal of even 

 the greater portion of the twigs and the 

 branches by no means entirely destroys 

 the value of the tree. The tree will push 

 its new top vigorously and in two or 

 three years be in full bearing again. 

 Where the blight has run past the main 

 forks, however, a serious question is in- 

 volved. Where inefficient, unskilled labor 

 has to be used we advise pulling out all 

 trees where it has run down the bodies, 

 or has infected the root system. Many 

 growers, when the matter is explained 

 to them, condemn such trees and root 

 them out, and thus, of course, simplify 

 the matter. On the other hand, it is 

 possible to effect an eradication of the 

 blight by carefully cutting out the bark, 

 and even the discolored wood, entirely 

 beyond the limits of the infection. An 



