Soil Moisture Affects the Performance 

 of Mcintosh Apple Trees on M.7A, 

 M.26, M.9/MM.106, and M.9/MM.111 

 Rootstocks 



Wesley R. Autio, William J. Lord, and Peter L. M. Veneman 

 Department of Plant & Soil Sciences, University of Massachusetts 



Apple trees on a given rootstock often per- 

 form differently on different orchard sites. 

 Likely, the predominant site factors governing 

 these differences in performance are soil charac- 

 teristics. To maximize productivity, growers 

 must choose the rootstock best suited to their 

 soil conditions. Few studies have specifically 

 evaluated the relationship of rootstock perfor- 

 mance and a soil characteristic, so this study 

 was initiated to relate performance of four 

 rootstocks and soil moisture. 



Ten sites were selected throughout Massa- 

 chusetts with a range of soil drainage character- 

 istics from somewhat excessively drained to 

 poorly drained. Locations of the sites and the 

 soil types are given in Table 1. Marshall Mcin- 

 tosh trees on M.7A, M.26, M.9/MM.106, and 

 M.9/MM. Ill were planted at the 10 locations in 

 1982. Red Chief Delicious/M.7A was included 

 for pollination. All trees received similar fertili- 

 zation. Weed-free strips (6 ft) were maintained 

 in the tree row using herbicides. All trees were 



Fruit Notes, Summer, 1991 



