Number of check rows required to select summer turnip rape for resistance to brown girdling root rot

Brown girdling root rot is a devastating disease of canola (Brassica rapa) in the Peace river region. Breeding for resistance to this disease up to now has relied on field screening, with every alternate row as a check. Examination of the distribution of brown girdling root rot from spaced rows of Brassica rapa ‘Tobin’ revealed that there would be a minimal loss of precision in breeding programs by reducing the frequency of check rows to one in four, which represents a considerable saving in cost compared with the current practice. Key words: Turnip rape, Brassica rapa, brown girdling root rot, resistance, selection technique