Yield comparisons of old and new cultivars of swedes (Brassica napus ssp. napobrassica) in Southland, New Zealand

Abstract

Yield trials of swedes (Brassica napus ssp. napobrassica) were analysed to compare the performance of recently released cultivars with the older cultivars they have replaced. Data from 1993/94 to 1997/98 were analysed using a mixed model analysis and G*e effects were examined. The recently released ‘Major Plus’ produced the highest fresh weight yield of bulb, 105 t/ha, 15% higher than ‘Doon Major’, the low dry matter (DM) cultivar that it has replaced. ‘Highlander’ had over 14% higher bulb DM yield than ‘Doon Major’ and the other main crop cultivars that have been replaced. ‘Tina’, the older cultivar with good clubroot and dry rot resistance, had a low yield. ‘Winton’ was bred to combine the disease resistance of ‘Tina’ with the yield of ‘Highlander'; it produced a bulb dry yield 5% higher than ‘Highlander’ and 47% higher than ‘Tina’. Estimates of total dry weight yield gave similar results and over the trial environments and years examined ‘Winton’ was also the most stable cultivar for total dry weight yield. © 2006 Taylor & Francis Group, LLC.