A Comparison of the Strip and Blended Method of Seed Production for polCMS Summer Rape Hybrid Cultivars (Brassica napusL.)

Abstract

Abstract Field seed production of hybrid summer rape (Brassica napusL.) at the University of Manitoba has been based on the cytoplas-mic male sterility system (CMS). Two methods of producing hybrid summer rape, the strip method and the blended method, were examined at two Manitoba locations. In the strip method, male (R-line) and female (A-line) parents were planted in separate rows utilizing a 1:1 row ratio. In the blended method, seed of the A-line and R-line parent are mixed in such a manner that the production field will consist of 90% A-line plants and 10% R-line plants. Seed yields ranged between 259 and 533 kg/ha from the strip method production fields, and between 646 and 1742 kg/ha in the blended method production fields. The percent hybridity ranged between 88 and 94% for seed lots from the strip method fields, and between 57 and 87% for the blended method fields. Since the seed lots obtained from the strip method fields were more consistent in their percent hybridity, it is recommended that the...