Faba bean (
Vica faba L.) is a widely popular grain legume that is used as human food and animal feed for its high nutritional quality
(Cazzato et al., 2012; Yasmin et al., 2020). It is one of the most vital winter crops for human consumption in the central part of the world
(Yadav et al., 2017). The crop contributes to soil health improvement through biological N-fixation (
Gasim and Link, 2007;
Rubiales and Mikic, 2015). It is also used as an excellent component of crop rotations, something that has been very much ignored in recent cropping when there is a crucial need to reduce the impact of chemical fertilizers on the environment. Due to its numerous uses, high nutritional quality and capability to grow over a wide range of agro-climatic conditions, faba bean is appropriate for sustainable agriculture in many neglected areas and the crop has received greater global attention in recent years
(Nadal et al., 2003; Gasim et al., 2015). Faba bean can continue their growth and development at extreme temperatures
(Multari et al., 2015).
In Bangladesh, faba bean (
Vicia faba L.) is grown in some limited locality which is well known as
Kalimator, Baklakalai, Bhograkalai, etc. (Sheikh et al., 2020; Paul et al., 2021). It is grown in winter season as other pulses after the harvesting of transplanted
Aman rice with minimum tillage or sometimes directly sown in low lying areas as a relay crop with
Aman rice (
Biswas, 1988;
Paul et al., 2021). The increasing demand for protein in human and animal consumption and the high cost of animal sources such as meat and fish have resulted in increased demand for legumes as a source of dietary protein and calories. Protein deficiency in human diet often leads to protein-energy-malnutrition causing various forms of anemia (
Shukla and Mishra, 2020). We are accounting for chronic protein deficiency for the increasing population; the traditional legumes (lentil, mungbean, grass pea, peas, chickpea and black gram) are grown in Bangladesh. These legumes are low yielding and very much susceptible to insect pests and diseases and requires more agricultural practices. Therefore, now a days underutilized crop faba bean is showing its promise for its large size, high yielding, resistance to pests and diseases, and requires less input. So, the crop would undoubtedly play an important role in crop diversification as well as protein supplementation programs in Bangladesh.
Global aspect and trend of Faba bean cultivation
Faba bean is currently produced in more than 66 countries over the world (
Merga et al., 2019). Twenty years of data (2000 to 2019) showed that Asia is world’s leading continent covers 41% production followed by Africa and Europe with the production (Fig 1). Fig 2 shows that China (1.74 million tons), Ethiopia (1.01 million tons), United Kingdom (0.55 million tons), Australia (0.33 million tons), France (0.18 million tons), Sudan (0.16 million tons), Germany (0.16 million tons), Italy (0.13 million tons), Lithunia (0.13 million tons) and Egypt (0.10 million tons) are the top ten faba bean producers in the world in 2019 (
FAO, 2021). Compared to the year 2000, the area cultivated for faba bean production increased slightly from 2.51 to 2.58 million ha in 2019. However, the total production quantity of faba bean increased apparently from 3.78 to 5.43 million tons in 2019 from 2000 (Fig 3). In between 2000 and 2019 the area of faba bean cultivation decreased in 2006, 2014 and 2019 compared to subsequent previous year although production decreased in respect to area in 2006 and 2014, whereas in 2019 production increased compared to 2018 even though area decreased (Fig 3). The global pulse crops data of 2010 to 2019, revealed that the annual average area 3.38 to 4.55 million ha and production 4.74 to 6.0 million tons (
FAO, 2021). Globally, the areas cultivated for faba bean have decreased highly from 5.40 million ha (1961) to 2.58 million ha (2019) and as against this, the average yield bean has increased 0.90 t ha
-1 (1961) to 2.11 t ha
-1 (2019) (
FAO, 2021). Despite the decreasing acreage, however, productivity per area has tended to increase, due to reduced susceptibility to abiotic and biotic stresses
(Link et al., 2010; Sillero et al., 2010; Singh et al., 2012; Karkanis et al., 2018). The statistical data on faba bean acreage and production are not available in Bangladesh. Although pulse crop covered an area of 0.36 million hectares with the production of 0.16 million tons including a very little contribution from faba bean in Bangladesh (
BBS, 2020).
Importance of faba bean
Nutritional values
Faba bean (
Vicia faba L.) is a unique legume crop because of its very rich nutrient content which also serves as an outstanding source of proteins, complex carbohydrates, dietary fibre, choline, lecithin, minerals and secondary metabolites such as phenolics. Interestingly, in contrast to cereals, faba bean is found to contain a high level of lysine and arginine, which may complement the low levels of those in cereals. Faba bean could be used in combination with other plant-based foods to improve the quality and quantity of the proteins provided in a meal
(Multari et al., 2015). Much consideration is now being compensated on the antioxidant capacity of the flavonoids and the phenolics
(Sinha et al., 2013). Kumar et al., (2015) found the different nutritional parameters in variable concentration among different germplasms of faba bean
viz. total soluble protein 20-32%, free amino acids 188-348 mg/100 g, starch 27-33%, reducing sugars 85-188 mg/100 g, non-reducing sugars 0.7-1.7% and total soluble sugars 0.8-1.9%.
Mortuza et al., (2009) found from the chemical analyses of faba bean contains protein (30.57%), crude fat (3.22%) and fibre (2.73%), ash (3.61%) and carbohydrate (59.87%) and essential amino acids with lower methionine/cystine and higher lysine content. Faba bean is a rich source of fiber and non-nutrient secondary metabolites shown to be beneficial to human health
(Aune et al., 2011). However, the chemical composition is strongly influenced by genotype, environment as well as management practices
(Mona et al., 2011; Cazzato et al., 2012; Witten et al., 2015; Karkanis et al., 2018).
Faba bean seed contains phytic acid, saponins, lectins, alkaloids, and others, which have anti-nutritional functions and reduces the digestibility of seeds (
Gupta, 1987). However, some domestic approaches such as soaking and cooking at high temperatures markedly reduce and often totally abolish them from the seed
(Luo et al., 2009). Tannins are phyto-chemicals abundant in faba beans which are one of the main anti-nutritional factors that reduce the bioavailability of proteins and minerals
(Sinha et al., 2013). They negatively affect the digestibility of proteins present in the food matrix (
Papadopoulou and Frazier, 2004). As tannin are mainly located in the seed hulls
(Helsper et al., 1993), the process of dehulling leads to a drastic reduction
(Alonso et al., 2000), while soaking and autoclaving inactivate trypsin inhibitor activity (
Luo and Xie, 2013;
Shi et al., 2017).
Uses as food and feed
Faba bean is popular worldwide for its nutritional value and vast area of uses. It is used as human food in unindustrialized countries and as animal feed, mainly for pigs, horses, poultry and pigeons in developed countries (
Singh and Bhatt, 2012a). In Bangladesh, it is usually used as
a dal (soup) for humans. It can be used as a vegetable, green or dried, fresh or canned (
Gasim and Link, 2007). It is one of the most important winter crops for human consumption in the Middle East (Martin
et al., 1991). Faba bean has been considered as a meat extender or substitute and as a skim-milk substitute (
Oplinger, 1982). It also faba bean cultivated for green manure, but more generally for store feed (
Singh and Bhatt, 2012b). Faba bean seed contains low LGC (Least gelation concentration) value indicates that faba bean has a larger capacity to form gel than other seed flours (
Sathe et al., 1982,
Oshodi and Adeladun 1993,
Kaur and Singh, 2007) and consequently may be an asset of faba bean for the making of curd, pudding or as an additive to other gel-forming materials in food products. Large-seeded immature beans are eaten as a vegetable after boiling and roasted seeds are eaten like peanuts in India and other countries (
Yitayih and Azmeraw, 2017). The high protein content of faba bean seeds brands this seed well adapted to poultry nutrition. When faba bean is comprised of levels as high as 250 g/kg in broiler diets, it can substitute soybean meal in a huge portion. However, in different animal species, it has been detected that extreme diets covering about 50% faba beans significantly reduced the absorption of Zn and Mn
(Rubio et al., 1994). Proskina and Cerina (2017) reported that adding legume (field peas and faba beans) to the broiler feed ration resulted in a significant live weight increase (5.74-11.95%) at the selling age, a decrease in the feed conversion ratio by 0.61-6.06%, and decrease in the product unit cost (15.34-37.06%) as well as an increase in the production eficiency factor (8.70-48.54), compared with the control group.
Medicinal uses
Faba bean has been endorsed with its certain medicinal values and in this direction, research is going on the potential use of faba bean as a treatment in Parkinson’s disease. People with Parkinson’s disease are unable to produce dopamine, which helps as a chemical messenger in the brain and helps regulate important motor and cognitive functions (
Sinha, 2012). Commonly Parkinson’s disease patients are treated with synthesized L-Dopa. Synthesized L-Dopa is expensive and often related to a variety of side effects including nausea, vomiting, low blood pressure, drowsiness, and restlessness
(Patil et al., 2013). Therefore, consuming natural sources of L-Dopa to avert potential side effects has been recommended
(Singh et al., 2013; Patil et al., 2013). Faba bean is a good source of levodopa (L-dopa), a natural precursor for the various neurotransmitters like dopamine
(Upadhvay et al., 2014). L-Dopa, a precursor of dopamine currently used as a major ingredient in treating Parkinson’s disease and hormonal imbalance
(Surwase et al., 2012; Hu et al., 2015; Ramirez-Moreno et al., 2015; Etemadi et al., 2018). L-dopa is also a natriuretic (urinary excretion of sodium) agent, which might help in controlling hypertension
(Jambunathan et al., 1994). Some also use faba beans as a natural alternative to drugs like Viagra, citing a link between L-dopa production and the human libido (
Hulse, 1994). It is estimated that the annual world demand for L-Dopa is about 250 tons with a market value of about $101 billion
(Patil et al., 2013). Cultivation of crops that are rich in natural L-Dopa to overwhelmed side effects and the high cost of production of synthetic L-Dopa thus seems justifiable
(Singh et al., 2013; Patil et al., 2013). Fru¨hbeck et al., (1997) noted that beside protein and energy supply, effects of faba beans-enriched diet have been described in humans where significant decrease in plasma LDL (low-density lipoprotein) -cholesterol levels. Faba bean and derivatives could represent a suitable food in treatment of diabetics, in hypertension and may help to prevent cardiovascular disease (
Madar and Stark, 2002). The antioxidant, anti-inflammatory and anti-diabetic properties of faba bean could be involved (using polyphenols) in the protection against the development of human diseases
(Turco et al., 2016).
Soil health improvement
The amount of N fixed by the symbiotic relationship between legumes and the soil rhizobia bacteria is determined by the relative reliance of the crop on biological nitrogen fixation for growth and the amount of N accumulated by the crop over the growing season (
Jensen and Hauggaard-Nielsen, 2003). Numerous environmental factors are hindering the agricultural production, for example the calcareous soils suffering from ferric and phosphoric deficiencies. In those soils, legumes were measured as an alternative solution to retrieve a fertile soil without the abusive use of chemical fertilizers
(Wissal et al., 2020). Faba bean is the highest nitrogen-fixing annual legume making it an excellent rotational crop. It can fix uphill of 90% of their nitrogen desires, which means less nitrogen fertilizer needs to be applied. There has been a certain subjective signal that cereal crops succeeding faba bean can see a yield upsurge of 10 to 15%. This could be a result of the nitrogen that is slowly released from the faba bean stubble.
Murinda and Saxena (1985) reported that faba bean fixes extra nitrogen (135 kg N ha
-1) than lentil and chickpea. Nitrogen sources from N
2 fixation and soil will generally be utilized more competently since the greater competitive ability of the cereal element for soil mineral N (or fertilizer N) results in reduced uptake of soil N and higher requirement upon N
2 fixation by intercropped faba bean compared to a faba bean crop
(Hauggaard-Nielsen et al., 2008). Faba bean used as green manure which is a keystone for improving the sustainability of agro-ecosystems due to their beneficial impacts on fertility building (
Álvarez-Iglesias et al., 2015). Incorporating legume residues into the soil as green manure improves soil properties such as organic matter content, bulk density, porosity and field capacity
(Mandal et al., 2003; Salahin et al., 2013; Adekiya et al., 2017) and consequently increase yield of field crops
(Bilalis et al., 2012; O’Donovan et al., 2014).
Used as control biotic agents
Integrated weed control is essential for successful crop production. The seedling stage of faba beans is poor competitors with weeds
(Ali et al., 2000). Álvarez-Iglesias et al., (2014) reported that biomass of faba bean is a promising material for weed control in sustainable cropping systems because faba bean aqueous extracts significantly inhibited the germination and early growth of weeds thus enhances crop growth.
Kaletha et al., (1996) and
Nava-Rodríguez et al., (2005) confirmed the
in vitro effects of faba bean aqueous leachates and obtained promising allelopathic effects on weeds and crops. If faba bean aqueous extracts used as a potential herbicide for its use in the field, it is basic to ensure its capability of controlling most weeds without damaging the crop (
Álvarez-Iglesias et al., (2014). The major insect pest and diseases reduce the quantity and quality of faba bean. Black bean aphid (
Aphis fabae L.) is devastating pest of faba bean causing great yield loss
(Subedi et al., 2018) through direct feeding damage and transmit plant viruses
(Nuessly et al., 2004). Aqueous leaf extracts of faba bean have insecticidal and repellent properties that could be used as an alternative of chemical insecticides in an integrated pest management program to
Aphis fabae (
Meradsi and Laamari, 2016).
Peyvast and Khorsandi (2007) reported that different parts (flowers, leaf, seed and seed hull) of faba bean (broad bean) extracts could produce relative highly antimicrobial activity against various bacteria
. Leaf extract in distilled water showed higher antibacterial activity against gram positive bacteria
Bacillus sabtilis, Staphylococcus aureus, Micococcus pyogenes and gram negative
Escherichia coli, Shigella sp. and
Serratia marcescens.
Major challenges and opportunities of faba bean cultivation in Bangladesh
Lack of potential variety is the key constraints of faba bean cultivation in Bangladesh. Although so many genotypes are available sporadically over the country but not yet recommended nationally considering agroclimatic conditions. Besides, yield potential of faba bean highly responsive to both abiotic and biotic agents. Their relative importance, however, varies depending on the agro-ecological conditions of the crop production. The main abiotic stresses in Bangladesh include early cold in the crop season, drought at various stages of growth and heat during the reproductive growth and pod filling stages. Salinity also constraints of the production of faba bean in the vast coastal areas of Bangladesh.
Weed is the major constraints that reduces yield loss of faba bean in Bangladesh. The major insect pest and disease which reduces the production and quality of faba bean are aphids, mite, pod borer and thrips. Various leaf fungal diseases
viz. chocolate spot, blight, rust, powdery mildew along with root and stem rots and pod spots are very common in faba bean crop in Bangladesh. Root rot and stem rot hampers crop growth properly thus subsequently damage the crop. Rust appears as orange-brown pustules with a light green halo on leaves, which can spread to stems and pods quickly in faba bean crop and drastically damages the faba bean field. Long periods of high humidity and high temperature is very common in some agro-ecological zones of Bangladesh during pod formation stage which promote the switch from a non-aggressive phase to an aggressive phase of the different leaf diseases like chocolate spot, blight and rust thus damages the foliage, limits photosynthetic activity and hamper faba bean production in Bangladesh.
Bangladesh is self-sufficient in grain crop production although it is quoted as one of the most vulnerable countries to climate change due to its geographical position. Now a day’s nutritional security is the main issue and challenges for the researchers of Bangladesh. Most of the low income people of Bangladesh fulfill their protein requirements through pulses. Over growing population and low yield of pulses expanded the gape of national demand. But due to the ever-increasing demand and import of pulses, Bangladesh has to spend on valuable hard-earned foreign currency (average USD 301,200.00) every year (
Bangladesh Bank, 2021). One of the possible ways to narrow down this gap between demand and supply could be increased through popularizing the underutilized faba bean cultivation. Faba bean can only be grown on diver’s agro-climatic conditions successfully, but it can also be produced on residual soil moisture, relatively more tolerant to biotic and abiotic stress, with minimum input (
Singh and Bhatt, 2012b). Less productive 1.0 million ha
Char lands (river basins)
(Karim et al., 2017), plain lands of hilly areas and unutilized land of drought prone areas of northern districts can be brought under faba bean cultivation. Nutritional properties of faba bean as well as it’s productivity that too with less agricultural inputs with other important pulse crops, it stands at par. It is an excellent source of protein, carbohydrates, and various minerals. Bangladesh has immense potentiality for faba bean cultivation which can take the production of pulses to a satisfactory level and farmers should be accustomed to the potentiality for wide-ranging expansion for their nutritional security.