Abstract
Eighteen bulbs of each of four cultivars and two inbred lines of swede (Brassica napus ssp rapifera L) were harvested at monthly intervals from 25 July 1988 to 6 March 1989. On average, dry‐matter yield increased from 50.8 to 277.0 g plant^−1^ by 14 November and then slowly fell to 240.5 g plant^−1^ on 6 March; and dry‐matter content rose from 99.5 to 118.9 g kg^−1^ fresh weight on 19 September and then slowly declined to 99.0 g kg^−1^ fresh weight in March. Hardness also increased from 25 July to 19 September but then remained constant. A hard high‐dry‐matter line, BWc4hca, and a soft lowdry‐matter line, CRdagaa, were the extremes for changes in sugar content. From July to October the average contents in g kg^−1^ DM of BWc4hca and CRdagaa were respectively: fructose 146.8, 224.3; glucose 206.8, 293.7; and total 390.7, 543.9. In contrast, from November to March their contents were much closer: fructose 187.9, 209.9; glucose 314.7, 323.I; and total 534.4, 549.3. Sucrose levels were much lower and more variable, but overall BWc4hca was highest, 34.1, and CRdagaa lowest, 20.6. The implications for swede breeding are discussed.