Effect of scarification and growing media on seed germination of Lupinus elegans H.B.K.

Lupinus elegans is a shrub with wide environmental tolerance and potential for ecological restoration and agroforestry systems. Little is known about the germination requirements of the species and propagation methods are needed to further study the potential and future use of the species. Four scarification treatments (mechanical scarification and immersion in concentrated sulfuric acid for 10, 30 and 60 minutes) and control were tested under growth chamber and greenhouse conditions. In the greenhouse four different growing media were tested. Highest germination under growth chamber conditions was obtained with acid scarification for 60 minutes (89%). Highest shoot emergence was obtained with the same scarification treatment under greenhouse conditions (54%). Under greenhouse conditions, pulling together all scarification treatments, there was considerable variation on shoot emergence depending on the growing media (28% to 48%). Mechanical scarification was also efficient in promoting germination for growth chamber conditions (39%) and shoot emergence for greenhouse conditions (48%) but it was labor intensive. Lowest germination was observed for untreated seeds for growth chamber conditions (7%) and shoot emergence was also lowest for untreated seeds under greenhouse conditions (3%). Our results suggest that acid scarification is an efficient means of promoting germination and that shoot emergence under greenhouse conditions vary considerably depending on the growing media selected.