Vigna aconitifolia

Vigna aconitifolia is a drought-resistant legume, commonly grown in arid and semi-arid regions of India. It is commonly called mat bean, moth bean, matki or dew bean. The pods, sprouts and protein-rich seeds of this crop are commonly consumed in India. Moth bean can be grown on many soil types, and can also act as a pasture legume.

Moth bean is a creeping annual herbaceous plant which grows to approximately 40 cm high. Yellow flowers on its hairy and densely packed branches develop into yellow-brown pods, 2 to 3 inches in length<ref name="one">Brink, M. & Jansen, P.C.M., 2006. Vigna aconitifolia (Jacq.) Maréchal. [Internet] Record from PROTA4U. Brink, M. & Belay, G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l'Afrique tropicale), Wageningen, Netherlands. <{{#invoke:citation/CS1|citation |CitationClass=web }}>. Accessed 15 November 2013.</ref> The seeds of these pods contain approximately 22–24% protein.<ref name="two">Stevens, J. (1994). Bean, Moth —Vigna aconitifolia (Jacq.) Marechal (HS554). Gainesville: University of Florida Institute of Food and Agricultural Sciences. Retrieved October 31, 2013 from [1]Template:Dead link</ref>

Due to its drought-resistant qualities, its ability to combat soil erosion and its high protein content, moth bean has been identified as possibly a more significant food source in the future.<ref name="three">Adsule, R. N. (1996). Moth bean (Vigna aconitifolia (Jacq.) Marechal). In Food and Feed from Legumes and Oilseeds (pp. 203–205). Springer US</ref> It has been suggested that its suitability as a grain legume in semi-arid Africa should be further investigated.<ref name="one" />

Description

Taxonomically moth bean belongs to the family Fabaceae (subfamily Papilionoideae),and genus Vigna. It is an herbaceous creeping annual that creates a low-lying soil cover when fully grown.<ref name="four">Sathe, S. K., & Venkatachalam, M. (2007). Fractionation and biochemical characterization of moth bean (Vigna aconitifolia) proteins. LWT-Food Science and Technology, 40(4), 600-610.</ref> Its stem can grow up to 40 cm in height, with its hairy and dense-packed branches reaching a span of up to 150 cm.<ref name="one" /> Yellow flowers develop into a brown pod 2.5 to 5 cm in length, which holds 4 to 9 seeds inside.<ref name="one" /> The rectangular seeds exist in a variety of colours including yellow-brown, whitish-green, and mottled with black.<ref name="three" /> Other widely cultivated species from the genus Vigna include the adzuki bean (V. angularis), the black gram (V. mungo), the cowpea (V. unguiculata, including the variety known as the black-eyed pea), and the mung bean (V. radiata).

History and geography

Moth bean is native to India, grown for food production and as a forage and cover crop.<ref name="three" /> It is predominately grown in India, although it has been cultivated in the United States, Australia, Thailand and other parts of Asia.<ref name="one" /><ref name="Dhillon2006">Template:Cite book</ref> 1.5 million hectares of land is used in India for moth bean production, producing approximately 0.4 million t/ha of seeds. While its presence in Sudan, Somalia and other tropical countries of Africa has been noted, it has not been a crop of great importance to this region. The potential of increased production in this region in the future has been suggested.<ref name="one" />

Growing conditions

Moth bean, a short-day crop, is one of the most drought-resistant pulses in India. Grown at altitudes up to 1300 m above sea level, it has a wide pH range (3.5–10) and can tolerate slight salinity.<ref name="one" /> While dry sandy soil is most suitable for production, moth bean can tolerate a variety of soil types.<ref name="one" /> The low-lying soil cover the crop creates helps prevent soil erosion by preventing moisture loss.<ref name="four" />

Optimum production of moth bean occurs between 24–32 °C, but has been shown to tolerate up to 45 °C during the day.<ref name="one" /> Growth is optimal at a constant temperature.<ref name="three" /> The moth bean is one of the most drought-resistant pulses in India, requiring little irrigation for production.<ref name="five">Khokhar, S., & Chauhan, B. M. (1986). Antinutritional factors in moth bean (Vigna aconitifolia): varietal differences and effects of methods of domestic processing and cooking. Journal of Food Science, 51(3), 591–594.</ref> While optimal annual rainfall for production is 500–750 mm, it is able to grow with 200–300 mm annually, and some yield has been noted at rainfall levels as low as 50–60 mm per year.<ref name="one" /> Propagation of moth bean is done by seed, preferably on a prepared seedbed, at an optimal temperature of 25–27 °C.<ref name="one" /> Fertilizer applications to moth bean are uncommon in India.<ref name="one" />

Other farming issues

Moth bean is grown for both human consumption and as a forage crop. Currently in India, moth bean is grown on its own or intercropped with other cereals, such as pearl millet.<ref name="one" /> It is also grown in rotation with cotton as a forage crop.<ref name="one" /> When grown as a forage crop, it is planted 7–34 kg/ha, and 10–20 kg/ha when grown as the only crop.<ref name="one" /> Row planting should be done 30–90 cm apart, with seeds sown 2.5–4 cm deep. It takes 75–90 days for moth bean to mature, and is frequently planted at the end of the rainy season.<ref name="one" />

A drawback to this crop is its difficulty to harvest. Mowers cannot be used due to the shape and density of the moth bean's branches, so the crop is typically cut with a sickle.<ref name="one" /> It is threshed and winnowed after being dried for approximately one week.<ref name="one" /> Hay yields from this crop are 7.5-10 t/ha, while forage matter yields range from 37-50 t/ha. Seed yields are currently low, ranging from 70–270 kg/ha.<ref name="one" /> However, research shows that this crop has the potential to increase in yield. Experimental seed yields of up to 2600 kg/ha have been recorded in the US and Australia.<ref name="one" />

Major pests and diseases

Moth bean is affected by mungbean yellow mosaic virus, for which silverleaf whitefly is the vector.<ref name="one" /> Root rot and seedling blight from Macrophomina phaseolina also cause damage, as well as some Striga species and the nematode Meloidogyne incognita.<ref name="one" /> There are some resistant cultivars to these pests and diseases.

Genetic stock

Little breeding work has been completed on the moth bean, but researchers have found that there is substantial genetic variation between moth bean germplasms.<ref name="six">Yogeesh, L. N., Viswanatha, K. P., Ravi, B. A., & Gangaprasad, S. (2012). Genetic variability studies in moth bean germplasm for seed yield and its attributing characters. Electronic Journal of Plant Breeding, 3(1), 671-675.</ref> The National Bureau of Plant Genetic Resources in New Delhi, India, houses more than 1000 accessions. Some improved cultivars such as ' CZM-2, CZM-3, ‘RMO-40’ and ‘RMO-225’are available in India.<ref name="one" />

Human consumption

Whole or split moth bean seeds can be cooked or fried. In India, particularly in the state of Maharashtra, moth beans are sprouted before cooking and used for making a spicy stew called matki usal.<ref name="monisha">Template:Cite book</ref> Matki usal forms the base of the Indian street food dish called misal pav.<ref name="seven">Nimkar, P. M., Mandwe, D. S., & Dudhe, R. M. (2005). Physical properties of moth gram. Biosystems Engineering, 91(2), 183-189.</ref><ref name="Hingle2015">Template:Cite book</ref> "Fried dal of the bean is used for making a savory dry snack, in India called dalmoth.<ref name="seven" /><ref name="one" /> The moth bean pods can be boiled and eaten.<ref name="one" /> The flour of the bean is used for making another savoury snack called bhujia.<ref name="one" />"

Animal consumption

Moth bean is also consumed as a forage crop by animals.<ref>Nene,Y L, Asian Agri-History Vol. 10, No. 3, 2006 (179–202)</ref>

Nutritional information

100g of raw, uncooked moth bean seeds contain 343 calories, 23 g of protein, 62 g of carbohydrate and 1.6 g of fat.<ref name="eight">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> As is the case with other legumes, this pulse does contain antinutritional factors that limit available protein.<ref name="five" /> However, research has shown that the moth bean contains considerably less of these factors compared with other legume grains, making it a more beneficial choice for consumption.<ref name="five" /> Soaking and cooking moth beans before consumption helps to break down antinutritional factors and makes the protein more digestible.<ref name="five" />

Constraints to wider adaptation

While its drought tolerance and high protein content could make the moth bean a potential crop choice for semi-arid Africa, a lack of management knowledge and the difficulty of harvest due to its density and creeping nature could make its spread to other parts of the world difficult.<ref name="one" />

See also

• Bean