20 MISCELLANEOUS PAPERS. 



SUMMARY. 



(1) The crown-gall disease of apple trees usuallj^ appears at or near 

 the union of the scion and root piece. 



(2) The crown-gall disease may be due to an excessive growth of 

 callus, or to an infection of fungi, bacteria, or other agencies at or near 

 the union. 



(3) Protection of the graft at the union will serve to induce a better 

 union and may also aid in keeping out disturbing factors. 



(4) In making grafts care should be taken to use root and scion 

 pieces of as nearly the same size as possible. 



(5) Grafts wrapped with cloth and with rubber yielded 85.1 per cent 

 and 86.5 per cent of smooth trees, respectively. 



(6) Ordinary thread grafts 3delded 68.5 per cent of smooth trees; 

 plain thread grafts with the union waxed, 44.2 per cent; grafts with 

 no wrapping, 54.8 per cent. 



(7) It is recommended that apple grafts be wrapped with cloth or 

 rubber. 



100—11 



