White lupin (Lupinus albus L.) is one of the 200 species of lupins, a genus of multipurpose annual legumes grown throughout the world both for their seeds used in feed and food, and for forage. Lupin seeds can be an alternative to soybean in all livestock species due to their high content in good quality protein (in the 30-40% range). Lupins also contribute to the sustainability of cropping systems (Lucas et al., 2015). The other main cultivated lupin species are the yellow lupin (Lupinus luteus), the blue lupin (or narrow leaf lupin (Lupinus angustifolius) and the pearl lupin (Lupinus mutabilis) (Jansen, 2006).
Morphology
Lupinus albus is an erect, bushy, annual legume that can reach 1.2 m high, with an indeterminate growing habit. It is many branched and deeply taprooted. The root can grow 70 cm deep. The stems are coarse, branched, slightly silky. The leaves are alternate, medium sized and digitally compound, bearing 5-9 obovate leaflets, 2-6 cm long x 0.5-2 cm broad, smooth on the upper face, hairy on the lower. The inflorescence is a terminal, 3-30 cm long, false raceme that bears many flowers. The flowers are pedicellated, typically papillonaceous, white to violet in colour. The corolla is 15-18 mm x 8-12 mm, the upper lip entire and the lower slightly 3-toothed. The pods are 3-6 seeded, narrowly oblong, laterally compressed, (6-) 9-15 cm long × 1-2 cm wide, yellow in colour (Clark, 2014; El Bassam, 2010; Jansen, 2006).
Uses
White lupin provides seeds for food and feed, fodder and green manure (Jansen, 2006). The seeds of earlier, alkaloid-rich bitter varieties used to be detoxified by soaking before being cooked for food and were consumed by low-income classes or during times of scarcity (Jansen, 2006). Modern sweet varieties do not require detoxification and are used in high-value specialties to enrich pastas, cake mixtures, cereals, and other baked goods (Clark, 2014). White lupin seeds are used to feed livestock and aquaculture species. The plant may also be grazed during late winter and early spring or cut for forage or silage. As a legume, white lupin plant is used for green manuring (in Southern Europe, it is traditionnally used in vineyards and olive plantations), and for soil improvement (Jansen, 2006; Duke, 1981). White lupin is a good honey plant and an attractive annual ornamental (Jansen, 2006).