Rural Industries Research & Development Corporation

The New Rural Industries
A handbook for Farmers and Investors

Moth bean

Introduction

Moth bean (Vigna aconitifolia) comes from the semi-arid regions of the state of Rajasthan in north-western India where it is claimed to be the most drought-tolerant legume grown in the country. It may have potential as a summer-growing annual crop for central or southern Queensland or northern New South Wales in those areas too dry for mung beans.

The drought tolerance of this bean may be due to the well developed tap root and/or the manner in which the plant produces a thick, low-lying mat, covering the soil surface and apparently reducing moisture loss. Such growth has advantages with erosion and weed control but presents difficulties with normal harvesting machinery since the inter-twined mat of material needs to be cut in strips so it can be harvested.

Moth bean seed is used as human food in India and Pakistan. The seed is cooked whole or split and the green pods can be cooked and eaten as vegetables. Seeds are also processed in dhal (a sprouted bean paste) or bhujia (a salted snack). The seed has 22-31% crude protein, with a biological value similar to that of mung bean but with lower digestibility.

Moth bean is currently grown in the north-western desert regions of India and Pakistan in those areas where mung beans may suffer from drought. This crop is also grown for seed in Myanmar, Sri Lanka, southern China, Thailand, Malaysia and southern Africa, and for fodder in the USA, in Texas and California. The only trials conducted in Australia to date have been initial seed trials.

Markets and marketing issues

Production of moth bean varies greatly within India, and all production is consumed within that country. No crop of moth bean should be contemplated in Australia unless its end-use and price have been prearranged. Average yields have ranged from 70-270 kg/ha, over areas ranging from 1.3-2.1 million ha. Experimental yields between 600 and 2600 kg/ha have been obtained in south-eastern Queensland.

Production requirements

Moth bean can grow well in hot climates with 500-750 mm of annual rainfall; if as little as
50-60 mm rainfall falls as three to four showers during the growing period, a good yield can be obtained. The crop does best on freely drained, light sandy soil and will not tolerate waterlogging. Initial vegetative development is slow and weeds at this stage of the crop's growth can smother the seedlings. Irrigation of moth bean is not recommended. Plants tolerate salinity and have been successfully nodulated over a wide pH range (3.5-10).

Varieties

The popular Indian variety Jadia (IPC MO 943; CPI 96934) was a satisfactory yielder in south-eastern Queensland in the
1992-93 summer. However, the best yielding variety in that season, and in other trials in the glasshouse, was IPC MO 950 (CPI 96943).

Because of differences in day length and temperature responses between varieties, overseas varieties may not be suitable for the Australian environment. At Gatton, moth bean has produced excessive vegetative growth, relative to the amount of seed eventually produced.

Agronomy

The land preparation required for moth bean is minimal. Standard machinery is satisfactory for sowing but care needs to be exercised with the use of press wheels behind sowing tynes. The low growth habit of the plant may render it impossible to gather with crop lifters if the plants are growing in furrows.

Planting rates of approximately 10 kg/ha, with 30-50 cm row spacings have proven most successful. Wider row spacings, with corresponding increase in the density of plants within the rows are desirable in drier areas, since the pods under these conditions tend to be carried on the tops of the plants. Moth beans have been intercropped with sorghum, millet or cotton in India.

In rotations, moth beans have been found to be of benefit to subsequent crops of millet. Low levels of fertiliser are applied to moth bean crops in India.

The best sowing time in south-eastern Queensland was between 15 December and 15 January. Maturity occurs 75-100 days after planting.

Pest and disease control

There are many diseases and pests which have been recorded in moth bean crops in India but they are rarely reported as causing serious losses, probably due to the environment in which is usually grown. Bean yellow mosaic leaf virus has been observed in trials in south-eastern Queensland, but losses were minor.

Key contacts

Key References

Beech, G.A. 1995. Variability in seed production of moth bean, Vigna aconitifolia (Jacq.) Marechal. M.Agric. Sci., thesis, The University of Queensland. 156pp.

National Academy of Sciences 1979. Moth bean. In `Tropical Legumes, Resources for the Future'. National Academy of Sciences, Washington, D.C.
75-80.

Kay, D.E. (1979) Moth bean. In `Food Legumes'. Tropical Products Institute, Ministry of Overseas Development, London. Crop and Product Digest, 3, 266-272.

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