Suniiiier Bearing Raspberries 



With the introduction of the Durham variety, described in Station Bulletin 

 No. 383, it became possible to produce a profitable fall crop of raspberries 

 in northern states. However, the northern part of New Hampshire has such 

 a short growing season that little fall crop ripened there. The next forward 

 step in raspberry breeding can be varieties which will ripen on the new canes 

 in mid-summer at the same time that ordinary raspberries are ripening from 

 over-wintered canes. This seems to be a definite possibility. Plants showing 

 such early fruiting on primocanes have been discovered in several different 

 progenies. Descendents from Ruhus Odoratus x Durham have produced a 

 summer crop ripening in July from canes which came from the ground the 

 same season. These seedlings have not been good enough to name as a variety. 

 A red raspberry seedling has been 

 discovered also which sends up 

 from the ground canes which ripen 

 berries in mid-summer. For breeding 

 purposes only, it has been called 

 Summer Red. There would seem to 

 be possibilities in getting varieties 

 which would ripen fruits on new 

 wood from such species as Riibus 

 chaniaemorus and Rubus arcticus. 

 Both of these species which we have 

 already used in breeding work send 

 up from the ground shoots that 

 blossom and fruit the same season. 

 Selected plants that bear early in the 

 summer on primocanes are being 

 crossed with other raspberries with 

 the objective of procuring raspberry 

 varieties which need not have canes 

 over-winter above ground for satis- _^ 



factory fruit crops. Susceptibility to is * * * 



cane diseases might also be avoided 



as the diseases might not carry over a sprout of a Summer-bearing rasp- 

 to the new sprouts. berry. 



Other Raspberry Breeding 



As mentioned in Station Bulletin No. 383, reciprocal crosses were made 

 between Durham raspberry and Rubus odoratus. The F^ hybrids had pink 

 flowers, a low stature, and proved to be less hardy than either parent. They 

 produced almost no suckers, although both parents sucker freely. It has 

 been possible to propagate the hybrids successfully by softwood cuttings. 

 Of 25 Fi hybrid plants, all proved sterile except one that did mature a few 

 scattered druplets. The somewhat fertile plant has been used in crosses with 

 other selected plants of Rubus and seems to work well as either a male or 

 a female parent. Some promising selections have come from crosses with 

 New Hampshire red raspberry. 



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