Effect of cultivar and harvest date on dry‐matter content, hardness and sugar content of swedes for stockfeeding

Abstract

AbstractEighteen 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.