which result in the development of watersoaked 

 areas. This disorder is referred to as watercore. 

 Watercore generally becomes more severe as 

 ripening progresses. Table 5 reports watercore 

 index values from this study for 1990, 1991, 

 1992, and 1993. The index used ranges from one 

 to seven, with one representing no watercore 

 and seven representing severe watercore. Fruit 

 from trees on B.9, MAC.39, P.22, P.2, or P.16 

 consistently were among the ones with the most 

 watercore when there were differences. Fruit 

 from trees on seedling, M.4, B.490, or P.18 were 

 consistently among the lowest. 



Taking all of these characteristics into con- 

 sideration, it appears that B.9 and P.16 consis- 



tently advanced ripening. MAC.39, P.2, and 

 P.22 were less consistent but also may have 

 resulted in an advancement of ripening. Seed- 

 ling, M.4, and P. 18 delayed ripening. B.490 and 

 A.313 were less consistent but also may have 

 delayed ripening. MAC.1, P.l, M.7 EMLA, M.26 

 EMLA, and C.6 were either intermediate in 

 their effects on ripening or were inconsistent. 



It is important for the grower to note the 

 potential effects that rootstocks can have on 

 apple ripening. In this planting, however, those 

 effects were variable and unpredictable, pre- 

 venting them from being exploited to expand the 

 harvest season. Hopefully, other rootstocks will 

 be found that have more predictable effects. 



16 



FruH Notes, Summer, 1994 



