PRUNING PRINCIPLES 107 



Leclerc du Sablon* ringed three or four-year pear trees before 

 vegetation started and a second lot after the first shoots had formed. 

 At intervals of two months thereafter trees from each group were 

 dug up and analyzed. The roots of the pears ringed in February 

 contained more reserve material than did the check trees not ringed, 

 while the stems contained less. After April, however, as a result of 

 assimilation by the leaves, the roots of the ringed trees were much 

 poorer in reserve material than those of the control trees. On the 

 whole the experiment is believed to show that toward the end of 

 winter and the beginning of spring the reserve material goes from 

 the roots to the stems. From May to October the current of elab- 

 orated material is from the stems toward the roots. 



Hedrickf and his assistants have reported unfavorably on ringing 

 tomatoes and chrysanthemums. The tomatoes showed a loss in 

 fruit production and in the leaf and root systems of the plants. The 

 chrysanthemum plants also suffered. 



Paddock carried out experiments in ringing grapevines. The 

 process generally hastened maturity of the fruit, depending on sea- 

 son, variety and conditions of vine. On the whole the operation is 

 devitalizing and care is required in its application. 



101. Ringing fruit trees.^ The object of ringing fruit 'trees is to 

 induce unproductive trees to set fruit. Briefly stated, the theory of 

 the operation is : That the removal of a band of bark through the 

 cortex and bast of a plant, at the period of most vigorous growth, 

 does not hinder the upward passage from the roots to the leaves of 

 unassimilated sap through the outer layer of woody cells, but does 

 prevent the distribution, through vessels in the cortex and inner 

 bark below the wound, of assimilated food (20). The effect of this 

 action is to cause an extra amount of reserve material to be stored 

 in the upper parts of the plant for the production of fruit buds. 



Ringing plants consists in the removal of a band of bark through 

 the cortex and bast of the trunk. The term girdling is frequently 

 used to designate this operation, but since this name is usually as- 

 sociated with wounds made more or less deeply in the wood [and 

 since the operation] results in ultimate death, as when a tree is 

 girdled by mice or girdled for the purpose of killing, it is unfortu- 

 nately chosen. French writers use the phrase, "decortication an- 

 nulaire" (annular decortication or bark removal), which is more 

 exact than either ringing or girdling. The object of ringing is to 

 induce and increase fruitfulness. 



The object of the experiments was to determine, if possible, the 

 extent to which fruit trees may be ringed without permanent injury 



* Sur les effets de la decortication annulaire, Compr. Rend. Acad. Sci. (Paris), 

 140; 1553-1555. 1905. 



t N. Y. Agr. Exp. Sta. Bui. 288. 



N. Y. Agr. Exp. Sta. Bui. 151. 



$ Condensed excerpt from G. H. Howe's Bulletin 391 of the New York Agri- 

 cultural Experiment Station. 



