has cropped regularly every year since 1954 including 1956 when some 

 standard varieties lost a crop because of spring frosts. 



In 1948. a thousand more seedlings of Winter Banana x Mcintosh were 

 planted. Some of these cropped in 1955 and 1956. The seedlings that had 

 not been eliminated in the two preceeding years fruited in 1957. One tree 

 that produces bright solid red fruits of medium size and which has a flavor 

 resembling Jonathan has been saved for further observation. Five other 

 seedlings having fruits of some promise have been held also for further 

 testing. No seedling has yet proved sufficiently outstanding to warrant pro- 

 pagation. 



In 1956, a seedling designated NH :^C from the cross of Northern Spy 

 and Macoun was selected for limited propagation. Fruits of this selection 

 resemble Macoun in color and shape but they are much larger than the 

 Macoun. NH ^C has crisp good-keeping apples, but it has shown a tendency 

 to alternate bearing. Also in 1948. about 120 more seedlings of Northern 

 Spy X Macoun and reciprocal were planted. Some of these seedlings fruited 

 in 1947. None have been tagged yet for propagation. 



Triploid Apple Breeding 



Such important commercial apples as Baldwin and Gravenstein and some 

 others differ from common varieties in that they have three sets of chromo- 

 somes and are called triploids. The common varieties having two sets of 

 chromosomes are called diploids. Crosses were made between a tetraploid 

 Mcintosh and Winter Banana in an attempt to produce a triploid variety 

 of the Mcintosh type. 



A portion of a Mcintosh tree growing in the orchard of Roger Kimball, 

 Littleton, Massachusetts, produced giant fruits and proved to be tetraploid. 

 Flowers on the tetraploid branches were pollinated with Winter Banana 

 pollen on May 12, 1948, and set fruits abundantly. In the greenhouse during 

 the spring of 1949, 97 percent of the seeds from the Kimball 4n Mcintosh 

 X Winter Banana cross germinated. Thus Dr. Charlotte G. Nast, Botany 

 Department. University of New Hampshire, was able to obtain root tips for 

 a cytological examination from 371 individual seedlings out of the progeny 

 of 435 trees before they were transplanted to the open field in Greenland, 

 New Hampshire. All of the seedlings examined were found to have a triploid 

 count of chromosomes with three exceptions: definitely a diploid plant, a 

 seedling having less than 51 chromosomes and thought to be diploid, and 

 a pentaploid. This latter was a weak tree and died after two years. 



The triploid progeny of Kimball 4n Mcintosh x Winter Banana is rather 

 variable, being similar to the diploid progeny of Winter Banana x Mcintosh 

 in this respect. Some trees are weak; others are vigorous and make good 

 desirable trees. Only a few of these seedlings have fruited yet, though many 

 of the trees have blossomed. Late spring frosts have been a problem for the 

 past two years. 



In addition, several hundred open-pollinated seedlings from the Kimball 

 4n Mcintosh that are only of one year less age than the above cr.oss are 

 being grown. This progeny also shows many weak trees, though some make 

 a strong growth. These trees should fruit next year. 



