-8- 



5) There appeared to be a correlation between the occur- 

 rence of injury and site. Most injury occurred on 

 wind-blown sites and on sites with a high-water table 

 where the trees had previously shown symptoms o£ "wet 

 feet". 



Estimating crop loss can be difficult; however, I feel 

 we can approximate the actual crop loss using data supplied 

 to us by growers. The grower data indicate the following 

 crop losses. 



Trees Dead Trees Severely Injured Est. Crop Loss (bu) 



3800 10,615 188,965* 



Adjusted to reflect lost crop as replacement trees develop. 



As substantial important as these figures seem, most v/in- 

 ter injury went unrecorded. The injury that escaped notice 

 was the less severe type- -the poor tree vigor and the reduced 

 crop set and yield. This less severe vrinter injury probably 

 will cost our growers much more in the lost production than 

 the losses recorded above. 



ft****************** 



PROGRESS REPORT: HEIGHT CONTAINMENT ON SPARTAN AND I DARED TREES 



William J. Lord and Anthony Rossi 

 Department of Plant and Soil Sciences 



Pyramid-shaped trees on the more dwarfing rootstocks will 

 produce the bulk of their crop within reach from the ground, 

 without a ladder, and should produce well-colored fruits through- 

 out the tree. However, the most heavily planted size-control- 

 ling rootstock in Massachusetts is Mailing 7 (M7) , on which vig- 

 orous cultivars will produce trees 16 feet or taller. When 

 asked what they consider to be the ideal height for trees on 

 vigorous size-control rootstocks, the answer given by growers 

 generally varied between 10 to 14 feet. 



At present there is no rootstock more suitable than M.7 

 for our cultivars, with the exception of Delicious. However, 

 it may become necessary to lower or contain the height of trees 

 on M7 in the future because of the shortage of suitable harvest 

 labor. Therefore, questions to be answered are: (1) What is 

 a suitable pruning method for containing tree height? (2) What 

 is the influence of height reduction on yield? To answer these 

 questions we established a demonstration in 1976 on 12-year-old 

 Spartan and Idared trees on M7 planted at the Horticultural Re- 

 search Center at 20 ft. x 30 ft. spacing. We consider trees of 

 Spartan and Idared to have medium and low vigor, respectively. 



