20 



During the 1985 season, the grass in the block was longer than usual. 

 For the first time we noted a low incidence of fly specl< ( Zygophiala 

 jamaicensi s ) on Imperial Mcintosh, Liberty, MacFree, and NY 613^5-2. While 

 not a serious problem, flyspeck infections can reduce grade. Better manage- 

 ment of grass heights will help to eliminate this problem. 



Evaluation of disease-resistant apple trees allows us to see how they 

 perform under Massachusetts conditions. We now are ready, however, to 

 establish a block of di sease-res i-stant trees in a commercial orchard. This 

 will be done in the spring of 1986 in western Massachusetts with a 

 cooperating grower and through the Regional Extension Agent, Karen 

 Hauschild. As the trees grow and bear, they will be evaluated for perfor- 

 mance by a plant pathologist, entomologist, and pomologist. The grower will 

 also make critical evaluation as will other growers who see them at educa- 

 tional meetings held at the orchard. The test block will consist of 16 

 trees each of Rogers Mcintosh, Liberty, Freedom, Redfree, PRI Coop No. 23, 

 NY 7^*828-12, and NY 75^'i^-^, for a total of 112 trees all on M7A. 



Developing disease-resistant apple cultivars is a long and tedious pro- 

 cedure. The cultivars that are emerging are, however, improving all the 

 time. The two NY numbered accessions planned for the commercial orchard 

 trial were selected because they have many of the characteristics of 

 Mcintosh, yet are immune to scab and highly resistant to other apple 

 diseases. Better cultivars and insect management strategies aimed at 

 reducing sprays will result in quality apples available for direct sale to 

 consumers with the assurance that only a very few insecticide applications 

 were made. Ron Prokopy, University of Massachusetts Department of 

 Entomology, has demonstrated that he can use as few as two insecticide 

 sprays on his disease resistant apples and still produce a crop of nearly 

 blemish-free apples (Fruit Notes 50(2):2-5). 



All of the trees in the Disease Resistance Block will be labelled by 

 name. Please feel free to examine them when you visit the Horticultural 

 Research Center. For additional information on disease-resistant apple 

 trees, please contact Dr. William J. Manning in the Department of Plant 

 Pathology. 



Acknowl edgements ; We thank Tony Rossi and others at the Horticultural 

 Research Center for maintaining the block and applying insecticides. 

 Special thanks go to the Horticultural Research Center Trust Fund for 

 purchasing trees of 5 of the 7 apple cultivars to be used in the commercial 

 orchard planting and to Hilltop Nurseries for donating Redfree and PRI Coop 

 Trees. 



This activity is also supported by the University of Massachusetts 

 Cooperative Extension Service. 



