Indigofera arrecta Hochst. ex A. Rich.

A large shrub up to 3 m tall, often cultivated as an annual, with ca. 5 mm long flowers and 2-2.5 cm long straight pods, containing 6-8 seeds. I. arrecta, I. suffruticosa and I. tinctoria are closely related and intermediate specimens (possibly of hybrid origin) have been found.

When used as a cover crop, I. arrecta can only be grown in gardens with little or no shade. Plants prefer a hot, moist climate with a rainfall of no less than 1750 mm/year. The crop withstands waterlogging for up to 2 months.

I. arrecta is propagated by seed or cuttings. Seeds of I. arrecta possess a hard seed-coat and must be scarified. Sowing is done either on seed-beds or directly into the field, 3-4 seeds per hole, 60 cm apart within rows and 45-60 cm between rows. Land is prepared by ploughing or by hoeing. Germination takes about 4 days. When seed-beds are used, seedlings are transplanted at 4-6 weeks. Cuttings are made by dividing well-developed branches into pieces 30 cm long, which are kept for 2-3 days in a cool place before planting. Cuttings, 2-3 per hole, start rooting by the second week.

Husbandry: Weeding and earthing up is done about 1 month after planting and again 1 month later. Cover crops are slashed at regular intervals.

Diseases: I. arrecta can be attacked by Bacillus solanacearum.

Soil improver: It is also used as a cover crop and a green manure.

Tannin or dyestuff: I. arrecta is the chief source of blue dye. Medicine: The leaves are used in traditional medicines for epilepsy and nervous disorders and to heal sores and ulcers.