DRY-MATTER ACCUMULATION AND SEED YIELD OF DWARF AUTUMN-SOWN WHITE LUPIN (LUPINUS-ALBUS L)

DM accumulation and seed yield formation of the dwarf autumn-sown white lupin XA100 were compared with those of the tall cultivar Lunoble for 3 yr and at two plant densities to analyse to what extent the DM allocation to seed could be altered by dwarfism. At maturity, XA100 produced an average of 10.5 t ha(-1) of above-ground DM, whereas Lunoble produced 12.3 t ha(-1). Seed yield of XA100 (3.59 t ha(-1)) and Lunoble (3.36 t ha(-1)) were not significantly different, but the harvest index was 0.38 for XA100 and 0.32 for Lunoble. The reduction of the proportion of DM in XA100 stems was associated with an increase in the proportion of DM allocated to pods. The contribution of each pod order to total seed yield was different for XA100 and Lunoble, with XA100 producing more on the third and fourth branch orders. The low mainstem seed yield of XA100 was associated with late pod and seed abortion. XA100 mean seed weight was 0.287 g, and its seed protein concentration was 382 g kg(-1), both of which were higher than for Lunoble. XA100 was not selected for its yield potential. However, no agronomic problem associated with dwarfism was detected in this experiment. Consequently, the characteristics of the dward lupin have to be considered for the breeding of autumn-sown white lupin.