Lablab purpureus
- Easy to establish with large seed that can be sown directly into moisture
- High yielding with high quality forage
- Non-bloating
- Can be sown with summer grasses (e.g. Forage sorghum) to provide mixed forage system
- Drought tolerant once established
- Can be grazed, harvested for hay, or used as a green manure
- Short-lived
- Poor frost tolerance
- Low salt tolerance
- Intolerant of prolonged water logging
Plant: summer growing annual or short-lived perennial legume
Stems: thick, trailing and twining
Leaves: comprise 3 large rounded leaflets
Flowers: white or purple borne on long stems
Pods: flattened, usually 4 – 5cm long with 2 – 4 seeds per pod
Seeds: Seed colour can vary according to cultivar from white/cream to brown or black; characteristic fleshy white strip around half of circumference.
Lablab is a high yielding forage legume sown for grazing, forage conservation and as a break crop in sub-tropical and tropical farming systems. It is commonly used in mixed cropping-livestock systems in northern Australia and as a legume ley in sugar cane systems to address soil fertility decline.
Rainfall
Best suited to regions with 600 – 2500 mm annual rainfall and predominantly summer distribution.
Soils
Wide range of soils from deep sands to heavy clays provided drainage is good. Will grow on acidic to alkaline soils (pH water 5.0 – 7.5). Does not tolerate poor drainage or prolonged water logging.
Temperature
Tolerates light frosts and is more tolerant of low temperatures than cowpea.
Companion species
Grasses: Can be sown with tall forage crops such as sorghum and pearl millet.
Legumes: generally not grown in association with other warm season legumes.
Sowing/planting rates as single species
12 – 20 kg/ha
Sowing/planting rates in mixtures
5 – 8 kg/ha
Sowing time
Spring or summer depending on moisture availability.
Inoculation
Group J (Lablab, Pigeon Pea). Some sub-tropical soils may have suitable native rhizobia, however inoculation with the lablab rhizobia is recommended.
Fertiliser
Establishment fertiliser commonly not applied.
Maintenance fertliser
Commonly grown without fertiliser applications. When grown in sandy soil, it may benefit from applications of phosphorus and sulphur.
Grazing/cutting
Up to three grazings or cuttings are possible. Not tolerant of heavy grazing as this damages stems, but more tolerant than cowpea. Grazing should occur prior to flowering for maximum forage quality.
Seed production
Flowering and pod and seed production often continues over an extended period, especially if high water availability. ‘Rongai’ is late flowering and seed production is often affected by frosts in many cropping regions. Cultivar ‘Highworth’ is earlier flowering and avoids most frosts. Grain yields of 1 – 2.5 t/ha can be achieved, depending on cultivar, environment and management.
Ability to spread
Does not spread naturally. May appear in subsequent crops but usually only for 1 year due to low levels of hard seed.
Weed potential
Low weed potential due to short lived nature and poor seed longevity.
Major pests
Lablab roots can be attacked by nematodes and seeds by pod feeding and boring insects.
Major diseases
Lablab is less susceptible to root diseases than cowpea, and disease problems are rare.
Herbicide susceptibility
Highly sensitive to 2,4-D, M.C.P.A, 2,4-D-B and dicamba.
Feeding value
High nutritive value. Crude protein levels in the leaf range from 21 – 38% (commonly about 26%), in the stem from 7 – 20% and in the grain, 20-28%. Digestibility of leaves ranges from 55-76% (commonly over 60%).
Palatability
Leaf is highly palatable but stem has low palatability. The palatability of grain is low to moderate depending on variety.
Production potential
Seasonal yields of 2 t/ha leaf or 4 t/ha stem and leaf are common in the sub tropics. Liveweight gains in cattle have reached over 1.0 kg/head/day.
Livestock disorders/toxicity
Does not contain anti-nutritive factors such as tannins. No reported toxicities and non-bloating.
Group Cultivar Seed source/Information Early flowering Highworth Australian Herbage Plant Cultivars Late flowering Rongai Australian Herbage Plant Cultivars
Tropical Grasslands SocietyTropical Forages Database (SoFT) – Lablab
Stuart Brown & Bruce Pengelly
September 2007
