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It has been demonstrated that protecting feeder roots of apple trees 

 will result in increased growth, yield, and returns. The ARD diagnostic 

 service and integrated control program mentioned are the only sound 

 approaches available to growers at this time. Experiments are being con- 

 ducted to find control measures to substitute for the chemical soil treat- 

 ments. A better solution to these problems would result in economic 

 benefits to growers and the industry alike. 



Resources Available 



1. For parasitic nematode and replant chemical control practices refer 

 to the annual New England Apple Pest Control Guide. 



2. For ARD sampling information, nematode and ARD testing contact: 



Nematode Diagnostic and Orchard Management Service 

 Hills Bui Iding, Rm. 206 

 University of Vermont 

 Burlington, VT 05^05-0082 

 (802) 656-0477 



* * -> 



I UPDATE ON DISEASE-RESISTANT APPLES 



' William J. Manning and Daniel R. Cooley 



Department of Plant Pathology 

 University of Massachusetts 



The first disease-resistant apple trees at the Horticultural Research 

 Center in Belchertown were planted in 1978. Since that time, we have added 

 other new cultivars and numbered accessions as they have become available. 

 Descriptions and performances for some cultivars have been published in pre- 

 vious FRUIT NOTES issues (Vol. hS, No. 1; Vol. ^9, No. 2). Our purpose here 

 is to bring you up-to-date on the current contents of the collection and to 

 make you aware of plans to evaluate a new block of disease-resistant apple 

 trees to be established in a commercial orchard. 



There are now }k cultivars or numbered accessions in the collection at 

 Belchertown (Table 1). All of them are immune or highly resistant to apple 

 scab ( Ventur ia inaequal is ), but vary in their degree of resistance to black 

 rot ( Physalospora obtusa ) , cedar-apple rust ( Gymnosporang i u rn jun iper i - 

 viginianae ) , and powdery mildew ( Podosphaera leucotr icha) . Their reactions 

 are compared to those of the disease-susceptible cultivar, Imperial 

 Mcintosh. 



Foliar and fruit evaluations were made on September 10, 1985- 

 One-hundred leaves were evaluated per tree for percent incidence of black 

 rot, rust, and scab (Table 2). Foliar black rot was especially evident on 

 Imperial Mcintosh, King Luscious, MacFree, Nova Easygro, and Sir Prize. 

 Rust was evident on Imperial Mcintosh, King Luscious, and Sir Prize. Scab 

 was evident only on Imperial Mcintosh. These findings were consistent with 

 previous results. 



