45 



upon the tree in many respects is opposite to winter pruning. 

 The latter, as mentioned before, stimulates wood growth 

 while the former tends to lessen wood growth. As a rule, 

 any practice that checks wood growth tends to induce fruit- 

 fulness. Growers have taken advantage of this fact for 

 many years. In England the result is attained by root- 

 pruning. The method consists in digging a trench around 

 the tree at some considerable distance and severing some of 

 the roots. This interfers with the food supply and necessar- 

 ily reduces growth. In the famous Ozark apple region of 

 Missouri and Arkansas the same result is attained by ring- 

 ing or girdling the trunk or main branches of the tree, thus 

 checking the downward flow of sap. The roots in this way 

 are partially starved and are, therefore, unable to induce a 

 strong wood growth the following season. The work is 

 done during the growing season and, as a result, the wound 

 soon heals over. The growers in the Pacific coast region 

 practice summer pruning to check wood growth. A com- 

 .pjete or partial defoliation by insects, disease, or spray, in- 

 jury during the early summer seems to have the same effect. 



Just why the checking of wood growth should induce 

 the formation of fruit buds and how it exerts this influence 

 is not well understood. The theory has been advanced that 

 there is some inherent tendency on the part of the tree to 

 reproduce itself before it dies and that when anything in- 

 terferes with the natural processes the tree prepares for 

 death. This is not a satisfactory explanation and it is hoped 

 that the physiologists may be able to throw some light on 

 the subject in the near future. 



OPINIONS OF EXPERTS. 



For assistance in the preparation of this paper I havu 

 appealed to some of the best authorities in this country and 

 in Canada. Personal letters were sent to twenty-four dif- 

 ferent people, mostly college and experiment station horti- 

 culturists. Twenty-two replies were received. While these 

 replies brought out many conflicting statements with regard 

 to the time and method of doing the work, they mostly agree 



