Inbreeding and hybrid production in marrow-stem kale (Brassica oleracea L. var. Acephala D.C.)

The production of hybrid seed on a commercial scale is discussed. It is suggested that the special problems connected therewith are not great and that the hybrid seed need not be appreciably more expensive than seed produced in the normal way.A system for selecting desirable double-cross hybrids is suggested as a working pattern for a practical breeding programme based on this approach.