DISEASES, INSECTS, AKD ENEMIES. 26$ 



dressing: of sweet oil seems also of some service. But these are but. 

 paUiatives at the best, and in bad oases of canker the renewal of the soil 

 and also of the trees is the only satisfactory remedy. 



//. — Gum. 



This is a far more common disease among peaches than canker. Thiss 

 disease seems confined to stone fmits. It is very prevalent among' 

 cherries, and is also very destructive among peaches and nectarines. The 

 sap oozes out through every wound m the wood or bark, and forms into a 

 glutinous compound or gum. Hence the nanie of this disease. Its 

 causes are not very surely known. What may be called stimulating or 

 forcing treatment is sure to produce it. The trees are too often planted 

 in rich deep borders that have been heavily manured. They make large 

 gross roots in consequence. They are theur severely cut back to furnish 

 the lower portion of the trees with fruit-bearing wood. The sap for- 

 watded by these roots is thus confined to a too limited area, and the 

 excess runs or bursts out into gum. Ko doubt over-feeding and excessive 

 cutting back are also active causes of this disease. Poor or moderately 

 rich soils generally produce trees almost free from gum. A good anti> 

 dote to gum is found in summer pinching and pruning. The wounds 

 made by these processes are small, and they are also made at a time 

 when they heal quickly, thus preventing the direct exudation of the sap; — 

 one of the most active causes of gum. It, hewever, is doubtless often 

 caused by exceptional weather and peculiarities of locality. Sudden 

 atmospheric changes, resulting in an arrestment or qjiickened flow of the 

 sap, are likely to produce gum. It also seems to cling to certain localities. 

 Some gardens are hardly ever free from this disease ; in others it is seldom 

 seen, though the treatment and also the soil are very much alike. In 

 .bad cases the trees should be taken up and destroyed, for gum is diffi' 

 eult„ almost impossible, to cure. Lighter* cases should be carefully 

 scraped or washed off, and the wound dressed with oil. A strip of 

 common tracing paper or writing paper dipped in oil may be tied over 

 the wound. This will keep out the rain, and also moderate the direct 

 force ef the sun,. The latter seems to quicken the action of gum, 

 and partial shac!e is so far a palliative. In purchasing and plantiag 

 joung trees reject any that • have the lightest trace of gum, for the 

 merest taint of this disease in ther blood is .apt to overspread the 

 whole tree. 



