Abstract: The process of the present invention provides a convenient route for producing a predetermined hybrid variety of a crop which is capable of undergoing both self-pollination and cross-pollination. Cytoplasmic male sterile plants which also exhibit herbicide tolerance attributable solely to nuclear genes are the key plants for use in the present process. Economical bulk planting of the key plants with either maintainer or restorer plants is made possible. Following cross-pollination from a pollen source which lacks the herbicide tolerance unneeded plants effectively are eliminated by use of a herbicide. For instance, unwanted plants may be effectively eliminated immediately after pollination or prior to pollination in the succeeding generation (provided the requisite genes for herbicide tolerance are present therein) to make possible the existence in an unharmed state of a substantially homogeneous stand of the desired plants.

Abstract: The process of the present invention provides a convenient route for producing a predetermined hybrid variety of a crop which is capable of undergoing both self-pollination and cross-pollination. Cytoplasmic male sterile plants which also exhibit cytoplasmic herbicide tolerance (i.e., to a Type A herbicide) and tolerance to a different herbicide attributable solely to nuclear genes (i.e., to a Type B herbicide) are the key plants for use in the present process. The maintainer and restorer plants exhibit tolerance to different herbicides (i.e., to either a Type A herbicide or a Type B herbicide). The economical bulk planting of the parent plants is made possible during each step of the process.

Abstract: The process of the present invention provides a convenient route for producing a predetermined hybrid variety of a crop which is capable of undergoing both self-pollination and cross-pollination. Cytoplasmic male sterile plants which also exhibit cytoplasmic herbicide tolerance are the key plants for use in the present process. Such cytoplasmic male sterile plants may be readily multiplied and uniformly produced in accordance with the process of the present invention on a relatively economical basis by crossing with suitable maintainer plants. Economical bulk planting of the key plants with either maintainer or restorer plants is made possible. Following cross-pollination from a pollen source which lacks the herbicide tolerance unneeded plants effectively are eliminated by use of a herbicide.