Restricted branching narrow-leafed lupin - 3. Poor establishment

Establishment of restricted branching narrow-leafed lupins (Lupinus angusti folius L.) is often poorer than that of the normal branching counterparts. This study focused on establishment of the cultivars Tallerack and Merrit, as representative of restricted and normal branching lupins, respectively. Establishment from seeds of both genotypes harvested manually was high, but machine harvesting decreased establishment, at some sites markedly, and ge nerally more so in Tallerack than in Merrit. Establishment problems were re lated to germination and not emergence or seedling vigour. A similar contra st was found when seeds were harvested from several near-isogenic pairs of restricted- and normal branching genotypes. The basis of the generally grea ter sensitivity of the restricted branching genotypes to harvest damage, an d the interaction with environment is not clear. It is not related to diffe rences between genotypes in the seed size, proportion of hull in seeds or s eed moisture content, but hull composition and embryo morphology warrant fu rther study. Irrespective of its basis, higher harvest damage to seeds of r estricted branching genotypes is likely to be avoided by minimising harvest er drum speeds and harvesting at higher seed moisture concentrations.