Hayes and Garber - Cucurbit Breeding

278 BREEDING CROP PLANTS
made and 407 trees were grown. Some varieties were obtained
with larger fruits but these as yet have not been thoroughly
tested for hardiness.
Pears have been frequently tried in the Dakotas but have
failed for two causes (Hansen, 1915): (1) Lack of hardiness;
(2) susceptibility to blight. The Chinese sandpear, Pyrus
FIG. 64. Wolf, a hardy variety of plums which lacks quality of fruit. (Photo
loaned by Dorsey.)
sinensis Lindley, obtained from Dr. Sargent, of the Arnold
Arboretum, proved perfectly hardy and resistant to blight.
Various crosses between this species and cultivated pears belonging
to Pyrus communis have been made. Preliminary tests
have shown that some of the seedlings were blight resistant and
hardy. These results indicate that the problem of producing
FIG. 65. Burbank, a plum of high quality produced by Luther Burbank. It
lacks hardiness when grown in Minnesota. (Photo loaned by Dorsey.)
pears for the Northwest may eventually be solved. In a somewhat
analogous manner, Hansen (1911) has produced new plum
varieties by crossing the native sand cherry with Japanese plums.
This has resulted in a " happy combination of hardiness, rapid
growth and early bearing of tree, with large size and choice
quality of fruit."