Hayes and Garber - Cucurbit Breeding

BREEDING OF VEGETABLES 259
retained its resistance when grown in Iowa but seemed to lose it
when grown in Oregon, on the Pacific Coast. No very satisfactory
explanation has been offered for this phenomenon. It is
possible that a similar condition exists with flax wilt.
FIG. 62. A strain of Hubbard squash isolated by self-fertilization which is
comparatively uniform for the production of large fruits of uniform shape.
Minnesota Exp. Sta. (Courtesy of Bushnell.)
Flax strains resistant to wilt seem to lose their resistance when
grown for a few years in wilt-free soil.
Breeding Cucurbitaceae. Each botanical species of this
family in most cases constitutes a freelv inter-crossing group of
FIG. 63. A small fruited strain isolated from a commercial variety of Hubbard
squash by self-fertilization. Minnesota Exp. Sta. ( Courtesy of BushnelL)
varieties. The monoecious character of the plant encourages
cross-fertilization. In spite of these facts the authors believe
that in some cases progress may be made by breeding methods