DRY-MATTER ACCUMULATION AND PARTITIONING, AND SEED YIELD IN INDETERMINATE ANDEAN LUPIN (LUPINUS-MUTABILIS SWEET)

Despite the high oil and protein content of the seeds, the agronomic p otential of Lupinus mutabilis Sweet, a South American lupin species, i s limited because of its low seed yield and its uncertain maturity. Dr y matter accumulation and partitioning, and seed yield, of 2 genotypes (early-maturing LM34 and late-maturing LM268) were studied in 2 seaso ns at 2 densities at Lusignan, France. Total dry matter at harvest was , on average, 680 g/m(2). The mainstem and first-order branches mainly contributed to total plant biomass but pods were only produced on the mainstem. On average, across the different crops, the maximum leaf ar ea index (LAI) was 2.8. The duration of LAI above 2.5 was short and n ot correlated with the total dry matter production. The partitioning o f the dry matter varied according to the genotype. LM34 showed enhance d pod growth, its harvest index (HI) was 0.32, and seed yield averaged 1.28 t/ha. LM268 showed enhanced vegetative growth, both HI and seed yield were lower (0.16 and 1.13 t/ha, respectively), and whole plant m aturity was never reached. For both genotypes during the pod filling, no remobilisation of assimilates occurred from stems to pods.