RINGING AN UNSAFE STIMULUS TO FRUIT-BEARING* 



F. H. HALL. 



Sluggish fruit trees sometimes so tax the patience 

 A of their owners that any measure would be adopted, 



dangerous however drastic, if it promised to spur the laggards 

 remedy. into fruitfulness. For this reason the practice of 

 ringing trees and plants has occasionally, for a hun- 

 dred years or more, been recommended by plant physiologists and 

 used by growers to induce or to increase fruit-bearing. The method 

 has a theoretical chance for success; since the removal of a ring of bark 

 from tree trunk or plant stem may be made with comparative safety 

 at a certain time in the season and does not seriously interfere with 

 the upward circulation through the active, growing, new wood, but 

 does prevent the downward flow of the sap with the plant food formed 

 in the leaves. Thus the food for the whole plant, including the lower 

 stem and roots, is concentrated in the parts above the ring, and should 

 and does serve as a stimulus to the formation and development of 

 fruit buds. But is this stoppage of the normal circulation without 

 danger to the plant, or is the good great enough to overbalance any 

 such danger? Only careful experiments, continued for some time, 

 can answer these queries satisfactorily; and such tests, made at this 

 Station, prove that the practice is generally either of too slight ad- 

 vantage to pay for itself or too dangerous to justify its use even when 

 immediate results seem favorable. 



Tests reported in Bulletin No. 151 of the Station prove that ringing 

 grape vines of certain varieties produces earlier ripening and better 

 clusters, but that the vines suffer severely and do not become normalty 

 vigorous again for a long time, if ever. Bulletin No. 288 reports 

 ringing of herbaceous plants, like tomatoes and chrysanthemums, as 

 detrimental to the plants and productive of no compensating results 

 in earlier or better fruits. The present bulletin records tests of ring- 

 ing on apple, pear, plum and cherry trees, which indicate very limited 

 advantage for the practice under any conditions and decided disad- 

 vantages in most cases, particularly with the stone fruits. 



*A reprint of Popular Edition of Bulletin No. 391; for Bulletin see p. 613. 



[956] 



