Template:Chapters 5.11

5.11 -Mung Bean and its Effectiveness in Combatting Climate Change for Subsistence Farmers

Emma Ohirko, University of Guelph, Canada

Suggested citation for this chapter.

Ohirko,E. (2022) Mung Bean and its Effectiveness in Combatting Climate Change for Subsistence Farmers, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

Crop Information

Basic Crop Information

Mung bean is an annual crop which has many branches and typically grows to be between 60 and 76 centimeters tall (RSA, 2010). It looks very similar to the garden common bean plant. Mung bean is a dicot plant belonging to the legume family. The plant forms long, skinny pods which vary from green to brown in colour. The mung bean is considered a deep-rooted plant which grows both upright and vine-like (RSA, 2010). A typical mung bean plant flowers at the top in groups of twelve to fifteen flowers and is self-pollinating (RSA, 2010).

Mung bean is believed to have been domesticated in South Asia, however, the exact location is unknown (Isemura et al., 2012). Many wild versions of the mung bean exist in Myanmar and Thailand (Isemura et al., 2012). As much as 90% of the world’s present mung bean production occurs in Asia, with India being the largest producer (Isemura et al., 2012). Pakistan, China and Thailand are also important producers (Isemura et al., 2012). Most genetic improvements made to the mung bean are done at the World Vegetable Center (WVC) located in Tainan, Taiwan; this seedbank has released over 110 mung bean varieties around the world and holds over 6700 landraces (Isemura et al., 2012: Schafleitner et al., 2015).

Nutritional Information

Mung bean can be considered to be a fairly nutritious legume. It is a good source of the essential amino acids phenylalanine and leucine; it is also high in tyrosine (Yi-Shen, 2018). However, it is deficient in methionine and cysteine (Yi-Shen, 2018). Mung bean is generally a poor source of vitamins A and C but is rich in many minerals; overall this is considered an area for genetic improvement (Yang and Tsou, 1998). Mung bean is noted as a wonderful source of protein and starch (Yang and Tsou, 1998). Mung bean sprouts (the most common way of consuming mung beans) contain approximately 2 grams of protein per 100 grams, 3.6 grams of carbs per 100 grams, 0.65 milligrams of iron per 100 grams, 0.47 milligrams of zinc per 100 grams, 29 nanograms of folate per 100 grams and 0.09 grams of fat per 100 grams (USDA, 2019).

Growing Conditions

Mung bean crops are best grown in the warm season as they require 90 to 120 frost-free days (RSA, 2010). The ideal temperature range for growing mung bean is 27 to 30 degrees Celsius, with planting being suitable at temperatures of at least 15 degrees Celsius (RSA, 2010). Therefore, mung bean is typically grown in the summer and is considered to be a heat and drought tolerant crop (RSA, 2010). In order to get the highest yields, mung bean crops should receive moderate rainfall during the flowering to late pod fill period (RSA, 2010). High temperatures and low rainfall during mung bean flowering amount to lower yields (RSA, 2010). Mung bean plants are well adapted to sandy loam soils and drought-prone soils (Myers, 2003). Conversely, mung beans do poorly on heavy clay and/or saline soils, with the former limiting root growth (RSA, 2010). Mung beans are suited to well-drained soil with a pH of 6.3 to 7.2, requiring slightly acidic soils for the best growth (RSA, 2010).

Mung bean seeds should be planted 5 to 10 centimeters apart at a depth of 4 centimeters (RSA, 2010). Seedlings should then be thinned out to 15 centimetres apart (RSA, 2010). Row spacing is most successful at 75 centimeters to 1.2 meters apart (RSA, 2010). Mung bean seeds have a somewhat lower germination rate of about 50-60% (RSA, 2010). Planting equipment for soybeans and cowpeas is appropriate for seeding mung beans but it must be adjusted in order to account for its small seed size (RSA, 2010). Nitrogen fertiliser is generally not required for mung bean growth however, the use of Rhizobium inoculums is generally advised (RSA, 2010). In addition to this, mung bean also has phosphorus, calcium, magnesium and sulphur requirements (RSA, 2010). These fertiliser requirements are comparable to the needs of other legumes (RSA, 2010). About 5 to 10 kilograms per hectare of phosphorus fertiliser should be applied to dry-land mung bean crops (RSA, 2010). Furthermore, mung beans are sensitive to zinc deficiency and may require a post-emergence application of zinc sulphate, depending on the soil (RSA, 2010).

Weeding Requirements

Mung beans are not very competitive with weeds thus, adequate weeding is necessary to ensure proper yields (RSA, 2010). To combat this there are only a few herbicides registered for mung beans however, hand weeding mung bean crops 40 days after seeding can be highly advantageous (RSA, 2010). Additionally, inter-tillage is recommended once or twice a growing season and rotary hoeing should be done when necessary until flowers emerge (RSA, 2010). Weeding of damp plants is not recommended as this may spread bacterial and fungal disease to the crop (RSA, 2010).

Pest and Disease Control

Mung beans secrete a sweet, sticky substance which attracts many insects, thus causing insect pest control issues (RSA, 2010). Monocrotophus, omethoate or dimethoate should be sprayed at a minimum on 3, 7- and 14-days post-emergence (RSA, 2010). To avoid post-harvest pests, proper sanitation of storage facilities, total dry-down of seed and the application of vegetable oils to the seed is vital (RSA, 2010).

Mung bean may face pressure from various leaf and stem diseases, but this results in little damage to yields (RSA, 2010). The mung bean Yellow Mosaic Virus has the largest potential to damage mung bean crops in the Indian subcontinent (RSA, 2010). Most diseases and viruses facing mung bean crops are controlled through the use of disease-resistant seed varieties (RSA, 2010). Another important factor in controlling diseases is the removal of crop and weed debris at the time of seeding as these may be hosts of disease (RSA, 2010).

Smallholder Farmer Adoption Benefits

Mung Bean Drought Tolerance

Mung bean is believed to do very well under drought conditions; however, some varieties perform better in drought conditions than others (Bangar et al., 2019). Optimally, mung bean should receive 350-600 mm of rain per month, however, at minimum it only requires 50 to 200 mm of rain per month (Purwoko, 2014). Mung bean is most tolerant of drought conditions during the reproductive and vegetative phases and some mung bean varieties have been shown to produce higher protein content during drought stress (Bangar et al., 2019). This drought tolerance is achieved through tight regulation of leaf stomates -- pores that permit carbon dioxide input/oxygen release but also cause significant plant water loss known as transpiration (Pataczek, 2018). The fastest maturing varieties are ready for harvest 90 days after planting. Mung beans are competitive over other legumes in droughty soils (Myers, 2003).

Other Benefits from Growing Mung Beans

On the world market, mung beans may fetch a price which is double that of soybeans (Myers, 2003). Split, cracked, and otherwise damaged seeds, along with any other residual crop material can be fed to livestock (Myers, 2003). Because mung beans require a relatively short maturity period (sometimes as low as 60 days depending on the region), they can easily be double cropped after cereals or successfully intercropped with cereals (Myers, 2003; Bangar et al., 2019). This may allow mung beans to grow successfully alongside cereals without the need for any additional fertilizer inputs (Myers, 2003). Since mung bean is a food crop and drought tolerant, it has the potential to act as an “economic buffer” in the face of weather challenges and low world commodity prices when compared with other legumes (Myers, 2003). Mung bean leaves can be fed to cattle as forage (Myers, 2003). It can be grown for silage and chicken feed as well (RSA, 2010).

Mung bean also does well as a green manure, adding significant nitrogen and other nutrients to the soil. Mung bean is highly beneficial for its capacity to form a symbiotic relationship with root microbes that convert atmospheric nitrogen gas into ammonia fertilizer, a process termed biological nitrogen fixation. It is estimated that after cultivation, the nitrogen residue added by mung bean plants can be 36 to 52 kg of urea N ha-1, without the incorporation of residues. If residues are incorporated, mung beans can add 74 to 94 kg of urea N ha-1. This is particularly useful in conservation agriculture, and sustainable intensification of agriculture (Pataczek et al., 2018). If used in tandem with conservation tillage practices, growing mung bean can help increase biomass productivity of the soil, improve energy and water-efficiency and has the potential to increase profitability (Pataczek et al., 2018). The improvements that mung beans offer to the soil can have positive impacts which outlast the growing and harvesting of the mung bean plants themselves.

Smallholder Farmer Adoption Challenges

Growing mung bean has some constraints, the first of which being that mung beans are generally low yielding and have significant need and capacity for genetic development (AVRDC, 2016). This being said, some recent breeding collections have helped in the discovery of mung bean’s potential for salt and heat tolerance and yellow mosaic virus resistance (AVRDC, 2016). Mung bean could be bred for greater drought tolerance, improved nutritional profile and higher yields. Costs of producing mung bean are largely comparable to those of producing soybeans however they may be subject to higher transport and cleaning costs (RSA, 2010). As mentioned above, the germination rate of mung beans is also poor which may cause additional challenges considering mung bean is mainly grown for sprouts (RSA, 2010). It may be more difficult to find a buyer for mung bean seeds compared to other legumes therefore it is recommended that the farmer finds a buyer before seeding (RSA, 2010; Myers, 2003). There seems to be no reliable statistics available as to how much mung bean is grown and cultivated in Africa. Its growth may be limited by the fact that it may not be a culturally important food in some countries.

Further Critical Analysis

As stated above, producing mung beans is comparable to the production of soybeans in factors such as cost and inputs, but it provides up to double the price on the market. However, mung beans have lower yields than soybeans and do not have the same capacity to be used as animal feed. The drought tolerance of mung bean makes it more appealing as this may offer a stable income in time of weather variability. When compared to the cowpea, mung bean is the more competitive crop only in dry soils and areas more prone to drought, as is the same when compared to soybeans (Boe et al., 1991).

Conclusions

Overall, mung bean is a viable crop option for those with sandy loam, well-drained soil types which may experience seasonal drought before the flowering period of plant growth. It has a strong nutrient content and can easily be intercropped and double cropped making it a good additional source of income without requiring additional inputs. It is somewhat limited by the need for pest control, particularly weed control as it is not a very competitive crop.

Helpful resources to get started

https://avrdc.org/intl-mungbean-network/ This link provides access to mung bean workshops and is a connection to potential future development projects involving mung bean. It also includes basic information about the crop and its genetic breeding.

https://www.ncbi.nlm.nih.gov/pubmed/24438453 This link provides useful information about mung bean as medicine as well as information on its nutritional content.

https://homeguides.sfgate.com/plant-mung-bean-56151.html This link details basic, manual planting steps for the mung bean.

https://www.gardeningknowhow.com/edible/vegetables/beans/how-to-grow-mung-beans.htm This link provides useful information on growing mung bean and also provides tips for growing mung beans indoors.

https://indiaphile.info/a-healthy-snack-and-meal-sprouted-mung-beans-and-a-simple-saute/ This link features a simple way of preparing mung beans.

https://pubs.rsc.org/en/content/articlelanding/1997/ja/a701610g#!divAbstract This links discusses the use mung bean seedlings as bio-indicators of Arsenic contamination.

https://www.researchgate.net/publication/286306858_Use_of_raw_and_heat-treated_mung_bean_seeds_phaseolus_aureus_as_replacement_for_soybean_meal_protein_in_the_diets_for_sea_bass_lates_calcarifer_fingerlings_in_tanks_Effects_on_growth_performance_nutri This article discusses the use of treated mung bean meal as a replacement food source for sea bass.

https://onlinelibrary-wiley-com.subzero.lib.uoguelph.ca/doi/full/10.1111/jpn.12611 This links provides information on the use of fermented mung bean as feed for weaned pigs to improve their immunity.

https://search-proquest-com.subzero.lib.uoguelph.ca/docview/1491989865?rfr_id=info%3Axri%2Fsid%3Aprimo This link provides additional information about fermented mung bean as an additive to animal feed.

References

1. AVRDC. (2019, November 5). International Mungbean Improvement Network. Retrieved a. November 27, 2019, from https://avrdc.org/intl-mungbean-network/.

2. Bangar, P., Chaudhury, A., Tiwari, B., Kumar, S., Kumari, R., & Bhat, K. V. (2019, February 7). a. Morphophysiological and biochemical response of mungbean [Vigna radiata (L.) b. Wilczek] varieties at different developmental stages under drought stress. Turkish Journal of Biology, 43(1), 58-69. Retrieved from c. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6426646/.

3. Boe, A., Twidwell, E. K., & Rephart, K. D. (1991). Growth and forage yield of cowpea and a. mungbean in the northern Great Plains. Canadian Journal of Plant Science, 71(3), 709–715. doi: 10.4141/cjps91-104

4. Isemura, T., Kaga, A., Tabata, S., Somta, P., Srinives, P., Shimizu, T., … Tomooka, N. (2012, a. August 2). Construction of a Genetic Linkage Map and Genetic Analysis of Domestication Related Traits in Mungbean (Vigna radiata). PLoS ONE, 7(8). doi:

10.1371/journal.pone.0041304

5. Myers, R. L. (2003, November). Alternative Crop Guide Mungbeans. Iowa State University. a. Retrieved from https://www.extension.iastate.edu/alternativeag/cropproduction/pdf/mungbean_crop_guide.pdf.

6. Pataczek, L., Zahir, Z. A., Ahmad, M., Rani, S., Nair, R., Schafleitner, R., … Hilger, T. (2018). a. Beans with Benefits—The Role of Mungbean (Vigna radiate) in a Changing Environment. American Journal of Plant Sciences, 09(07), 1577–1600. doi: 10.4236/ajps.2018.97115

7. Purwoko, D. (2014). Using climate information for supporting mung bean a. plantation over Sumbawa region. Retrieved November 27, 2019, from https://www.weadapt.org/knowledge-base/climate-adaptation-training/using-climate-information-for-supporting-mung-bean-plantation-over-sumbawa-region.

8. Republic of South Africa (RSA). Directorate Plant Production. Mung Bean Production a. Guideline. (2010). Agriculture, Forestry and Fisheries, Pretoria. Retrieved from https://www.daff.gov.za/docs/Brochures/MbeanpGUDELINS.pdf

9. Schafleitner, R., Nair, R. M., Rathore, A., Wang, Y.-W., Lin, C.-Y., Chu, S.-H., … Ebert, A. W. a. (2015). The AVRDC – The World Vegetable Center mungbean (Vigna radiata) core and mini core collections. BMC Genomics, 16: 344. doi: 10.1186/s12864-015-1556-7

10. U.S. Department of Agriculture (USDA). (2019, January 4). Food Data Central Search Results. a. Mung beans, mature seeds, sprouted, cooked, boiled, drained, with salt. Retrieved from https://fdc.nal.usda.gov/fdc-app.html#/food-details/168499/nutrients.

11. Yang, R.Y. & Tsou, S.C.S. (n.d., 1998). Mungbean as a Potential Iron Source in South Asian a. Diets. World Vegetable Center (Tainan, Taiwan). International consultation workshop on mungbean. Retrived from http://203.64.245.61/fulltext_pdf/eam0122.pdf

12. Yi-Shen, Z., Shuai, S., & Fitzgerald, R. (2018). Mung bean proteins and peptides: nutritional, a. functional and bioactive properties. Food & Nutrition Research, 62, 10.29219/fnr.v62.1290. doi: 10.29219/fnr.v62.1290