-11- 



HEIGHT CONTAINMENT ON SPARTAN AND IDARED TREES 



William J. Lord and Anthony W. Rossi 

 Department of Plant and Soil Sciences 



In the January/February, 1980 issue of FRUIT NOTES we dis- 

 cussed our progress with height containment of Spartan and 

 Idared trees on M7a rootstocks. The objective of this demon- 

 stration was to answer 2 questions: (1) What is a suitable 

 pruning method for containing tree height?, and (2) What is 

 the influence of height reduction on yield? Below we have: 

 (1) summarized previously reported findings through harvest in 

 1979, (2) included our data and observations for the last 3 

 years, and (3) described containment pruning. 



Summary of Previous Findings Through Harvest, 1979 



Limb rotation in the top third of the crown of Spartan and 

 Idared trees on M7a rootstock was a suitable procedure for con- 

 taining tree height. The pruning demonstration was initiated 

 in February, 1976, and after dormant pruning in February, 1979, 

 the average height of the control trees was 2.5 feet greater 

 than that of the height- restricted trees. In spite of the 

 height difference, yields were not consistently reduced from 

 1976 through 1979 on the height-reduced trees (Table 1) . 



Table 1. Influence on yield from height reduction of Spartan 

 and Idared trees . 



Year 



Spartan^ 

 Height 



reduced 



control 



Idared' 



Height 

 reduced 



control 



1976 

 1977 

 1978 

 1979 

 1980 

 1981 

 1982 



Cumulative 

 yield 



6.0a 



4.0b 



10.4b 



9.6h 



6.5a 



14.0a 



13.1b 



64b 



w 



Bushels/tree 



8.0a 



5. 3a 

 12.5a 

 12.2a 



6. 3a 

 16.3a 

 14.4a 



76a 



61b 



73a 



y 



Trees planted in 1964; trial started in February, 1976. 



T 



Tree height 3/79: Control, 11.4 ft.; height-reduced trees, 



8.9 ft. Height 3/82: Control, 12.5 ft.,; height-reduced trees, 



8.5 ft. 



Tree height 3/79: Control, 10.6 ft.,; height - reduced trees, 

 8.3 ft. Height 3/82: Control 11.8 ft.; height- reduced trees, 

 8.1 ft. 



Means in any row for each variety followed by different letters 

 are significantly difference at odds of 19 to 1. 



w 



