EVALUATION OF NCINTOSH STRAINS IN MASSACHUSETTS 



Wesley P.. Autio, William J. Lord, and William J. Bramlage 



Department of Plant and Soil Sciences 



University of Massachusetts 



Many Mcintosh strains have been discovered throughout the years. Some 

 have been good and others not so good. To be accepted now, new strains must 

 have a high percent red color, yield well, and emerge from long-term storage 

 with high quality. To assess Mcintosh strains, a planting was established in 

 1979 at Green Acres Fruit Farm, Wilbraham, MA, including Morspur, Marshall, 

 Imperial, Macspur, Eastman, Gatzke, and Rogers Mcintosh on M.7A. This planting 

 is maintained by the grower. 



Trees have fruited since 1983, and the yields are reported in Table 1. 

 Most strains, with the exception of Eastman, yielded similarly each year and on 

 a cumulative basis. Eastman trees yielded the fewest fruit each year from 1983 

 to 1986, with a cumulative yield less than half that of the other strains. 

 Eastman also was the smallest tree in terms of trunk circumference (Table 1). 

 However, this fact did not account for the low yields, since they also were the 

 least yield efficient trees from 198:) to 1986 (Table 1). 



Table 1. Yield per tree (bu) in 198j through 1986 and on a cumulative basis, 

 cumulative yield efficiency, and 1986 trunk circumference of Mcintosh strains 

 planted in 1979. 



Yield per tree (bu) 



Yield Trunk 



efficiency circum. 



Strain 1983 198^ 1985 1986 Cumulative (kg/cm^) (cm) 



As fruit ripen their starch is converted to sugar which is observed easily 

 by staining the starch with an iodine solution. The pattern of staining 

 changes during ripening and can be categorized by comparing it to an index 

 chart. As the starch disappears the index value increases. For two harvests 

 in 1983, three in 1984, two in 1985, and one in 1986 starch index values were 

 determined with the starch-iodine test (Table 2). No consistent differences 



