Ringing and Scoring to Control Growth 

 of Apple Trees: Results from 1991 



Wesley R. Autio and Duane W. Greene 



Department of Plant & Soil Sciences, University of Massachusetts 



Regulation of vegetative growth is one of the 

 most important orchard practices. Tradition- 

 ally, pruning has been used by apple growers as 

 the sole means of regulating growth. Pruning, 

 however, results in a localized stimulation of 

 growth near the cuts, which ultimately reduces 

 fruiting potential. Frequently, a "vicious cycle" 

 can begin, where pruning is used to remove the 

 undesirable growth that resulted from a previ- 

 ous cut, and the tree's response is to produce 

 more undesirable growth which must be cut out 

 during the next dormant season. Many trees 

 presently in production are caught in this cycle 

 and thus are not fruiting to their full potential. 



Why Control Growth? 



A need to maintain a tree in a given space is 

 the most common reason for using growth con- 

 trolling techniques. Often, tree spread must be 

 controlled when soil conditions result in greater 

 than anticipated vigor, the wrong rootstock was 

 chosen for a particular cultivar, the scion vigor 

 was not integrated into the spacing decision, or 

 simply the trees were planted closer than they 

 should have been. In almost all situations, tree 

 height must be controlled to increase light pen- 

 etration to the lower portions of the tree canopy 

 and to reduce the need for tall ladders during 

 harvest. Pruning can provide both spread and 

 height control; however, two cultural tech- 

 niques are available which can control growth 

 and avoid the negative effects of pruning: scor- 

 ing and ringing. 



The Practices of Scoring 

 and Ringing 



Scoring, very simply, is the process of mak- 

 ing a single cut with a knife (a linoleum knife 



works very well) completely around the trunk of 

 the tree usually when terminal growth is be- 

 tween 4 and 6 inches long(approximately 7 to 10 

 days after petal fall). Ringing differs from scor- 

 ing only in the width of the cut. With scoring, no 

 bark is removed, so the cut heals relatively 

 quickly; however, with ringing a portion of bark 

 is removed, and depending on the width of that 

 portion, healing takes significantly longer. Gen- 

 erally, a pruning saw is used to make the scoring 

 cut. A "Turbo-cut" saw will make a cut approxi- 

 mately 1/16 inch wide. 



Basal Scoring and Ringing, 1991 



For whole-tree growth control, scoring and 

 ringing cuts are made between the soil and the 

 lowest scaffold branch. Table 1 shows the result 

 obtained in a study conducted at the University 

 of Massachusetts Horticultural Research Cen- 

 ter (Belchertown, MA) in 1991. In this experi- 

 ment, seven blocks of mature Gardiner Deli- 

 cious/MM.106 trees were selected, and one tree 

 in each block was either ringed, scored, or not 

 treated (control). Scoring and ringing were 

 performed on May 16, when terminal growth 

 was between five and six inches. Four- fruit 

 samples were taken throughout the harvest 

 season, and internal ethylene was used to deter- 

 mine when ripening began on the tree. A single 

 harvest of 30 fruit was made from each tree on 

 September 30 and weighed, and 10 fruit were 

 used to measure the percent soluble solids (sug- 

 ars) in a juice sample. Natural fruit drop from 

 each tree was assessed periodically from Sep- 

 tember 17 to October 16. 



Ringing and scoring caused a similar level of 

 growth reduction, resulting in approximately 

 half of the trunk growth experienced by the 

 controls (Table 1). Fruit size was unaffected by 



Fruit Notes, Summer, 1992 



