Production practices of Bambaranut in Uganda

Planting and cropping pattern

Planting BN, like most crops produced in the sampled regions, is synchronized  with  the  onset  of  rains,  being done mostly in March and April shortly after the first rains of the first season (Figure 3). A few also plant in June and July for the second season, in the Eastern region (Figure 3). In most cases, BN is planted in pure stand (79%) (Table 5), as a strip next to groundnut, and reportedly so since most practices are generally similar to that of groundnuts except that BN takes longer in the field. Where intercropping (21%) is practiced however, the most common intercrops are maize and cassava (Table 4). The reasons cited for these intercrops in Northern and Eastern regions, respectively were food security (67 and 83%), crop complementarity (architecture and non allelopathy) (16 and 39%), and higher yield (18 and 22%). Similarly for the intercrops, more women targeted food security (77%) and higher yields (24%) compared to the men (59 and 9%, respectively). Weeding BN is most often done twice, but occasionally may be less or more times depending on the weed situation in the field (Table 4). These regional trends are also exhibited for both gender and among the different age groups (data not shown), except as described for specific aspects earlier. Coinciding BN planting with the onset of rains and monocropping are practiced in nearly all BN production regions (Ibrahim et al., 2018; Berchie et al., 2013;  Hillocks  et  al.,  2012; Berchie et al., 2010b; NRC, 2006; Collinson et al., 1996). It is further reported that BN can be grown twice in a year in a region with a bimodal rainfall pattern (Berchie et al., 2013).

Although some parts of the study area tend to have a bimodal rainfall pattern, most parts have a unimodal pattern with a long rainy season stretching from March/April to November with sometimes a short dry spell in June (Wortmann and Eledu, 1999; Nsubuga et al., 2014).  This allows BN to be planted twice a year in Uganda as observed for the Eastern region. There is, however, little evidence to suggest that many farmers actually plant twice, as depicted in this study where farmers tend to plant in one of either season, but not both (Figure 3), with the first season (March-June) being the main season for BN planting. Further information from Niger and Zimbabwe reveal that where BN is intercropped, the most common intercrops are cassava and maize (Mubaiwa et al., 2018; Ibrahim et al., 2018; Hillocks et al., 2012). Nevertheless, intercropping BN is generally rare in large parts of SSA where land is not a limiting factor (Hillocks et al., 2012). With respect to weeding, two times weeding normally seems to be sufficient in most parts (Ibrahim et al., 2018; Hillocks et al., 2012; Berchie et al., 2010b; NRC, 2006), although additional weeding may be required (a third or spot weeding).

Earthing up

Another common practice done by 99.6% of all respondents is earthing up (also called mounding), during the second weeding (roughly 8 weeks after planting-WAP) (Table 4). A study in Burkina Faso revealed that the best time for earthing up is at 2 or 7 WAP, that is, before or after flowering for proper pod set and better seed yield (Ouedraogo et al., 2013). Bambaranut, unlike groundnut, has runner like stems along which flowers and subsequently pods are formed. If left uncovered, pods can be exposed to unfavorable environmental conditions resulting in poor yield (Ouedraogo et al., 2013), and arguably poor quality seeds, hence the need for earthing up. In other parts of the world, BN may alternatively be planted on ridges for the same reason as earlier stated, and for erosion control  and  avoidance  of  water  logging (Hillocks et al., 2012).

Harvesting

Harvesting is normally done in piece meal with first harvest predominantly in August and September while the last harvest is done in September and October (Figure 4). The beginning and end of the harvest period is largely determined by the time of planting and the entire harvest normally lasts about a month (Figure 4). Consequently, July is one of the last harvest months in Eastern region due to early first season (February) planting. Accordingly, the average relative maturity period by these planting and first harvest dates is 4 to 5 months for the landraces in the study sites (Figure 4). The reason for piece meal harvesting is likely due to the need to ensure a staggered supply of food and income and the need for seed preservation. Besides the timing from planting to first harvest, farmers use important changes during crop growth such as yellowing of leaves, colour and texture characteristics of a landrace, and drying of stems and leaves to determine harvest maturity and ensure good yield and high seed quality (Figure 4). However, whole plants are harvested at any one time and given the fact that BN can produce flowers for an extended period of time (up to 50 days) (Collinson et al., 1996), it is common to find pods and seeds on a plant at very different maturity stages. These and other factors such as soil and environmental conditions (Berchie et al., 2016; Berchie et al., 2012; Vurayai et al., 2011), photoperiod sensitivity (Kendabie, 2014; Berchie et al., 2013; Linnemann et al., 1995) and seed mixtures (NRC, 2006) make it difficult to determine the exact physiological maturity stage for a given landrace. Nonetheless, a report by Hillocks et al. (2012) indicated that the maturity period of most BN landraces in Zimbabwe is 5 to 6 months, while most landraces across SSA are said to mature in about 4 to 5 months (NRC, 2006).

Utilization of Bambaranut

Bambaranut is largely produced for food, but occasionally used as medicine and for cultural purposes (Figure 5).  As food, the nut is generally consumed in fresh and dry forms. In fresh form, the pods are boiled and seeds eaten as a snack mainly at the beginning of the harvest period (Table 5). In the dry form, the seed is either boiled as a whole grain or after being crushed. Choice of whole or crushed grains depends on the dish to be prepared. Boiled grains are either pasted with groundnuts/sesame paste or mashed with sweet potatoes. Crushed and dehulled dry grains make a special delicacy called ‘dek ngor’  /agira’   (in  Luo,  Northern  region)  or  ‘emagire’ (in Ateso, Eastern region) (Table 5). In some cases, the dry grain is soaked and toasted for a snack. Prior to cooking however, a number of procedures are applied to the dry grains to ease cooking and prepare the particular type of local dish (Table 5). These procedures are similar for both men and women in both regions (Table 5). Medicinal use, which featured more prominently among the older groups of ‘51-60’s (22.4%) and ‘over 60’ (22%) age groups, is reportedly for treatment of diarrhea and cough (chewed as raw or boiled fresh young/mature seeds). Additionally, the fully mature fresh or dry boiled seeds are used for treatment of aches (body and stomach), kidney problems, measles and relieving the pain associated with afterbirth in mothers of new born. They are also suggested by some, especially men, to act as an aphrodisiac. Culturally, there are several myths associated with Bambaranut, many of which seem to relate to conservation of the crop. Reports from this study suggest that BN is used to prevent crop damage from a ‘witch’ when planted along the boundary of groundnuts (both regions), prevent crop damage from hailstorms and lightning (Eastern-Teso), and can result in massive crop failure and death if one stops cultivating it (Northern-Acholi).

Similar to most traditional food crops in the country, BN is primarily produced for subsistence, whereby domestic food supply and seed maintenance are the major motivating factors for most communities. Consequently, the range of products from  such  a  crop  as  BN  is  very limited,  having only a few local products for domestic use and limited sale within the communities (Hillocks et al., 2012; Namazi, 2009). Yet several products can be derived  from  BN  due  to its relatively high starch and protein contents (NRC, 2006). In southern Africa for example, BN flour is widely used in making baked products, soups and porridge (Mubaiwa et al., 2018b). Similarly, milk from BN, demonstrated to be of comparable quality to  that  of  soybean  and shown to be acceptable to both mothers and their babies, is suggested to have great potential in the nutrition of under  age children (NRC, 2006). In Zimbabwe, canned BN beans are an important commercial product widely marketed in the urban areas of the country (NRC, 2006). Bambaranut can therefore be not only a major source of energy and proteins in the diets of communities, but a good source of income if production and utilization can be improved.  Additionally, consolidation of information on the reported medicinal uses and the basis for such  medicinal  properties  would further broaden the spectrum of BN utilization (Taahir et al., 2018).

Challenges of Bambaranut production and utilization in Uganda

Bambaranut farmers in the study area face several challenges, the most important ones being scarcity of seed, limited market and difficulty in harvesting (Figure 6).

Other relatively important challenges are post-harvest related and include poor storage facilities, damage by storage pests and diseases and difficulty in drying (prolonged drying time). These are cross cutting challenges in both regions, albeit with slight variations in importance (Figure 6). The underlying cause of seed scarcity is realistically linked to few farmers producing on relatively very small scale, while limited market is linked to low demand incited by relatively limited uses and lack of information discussed earlier. According to Obura et al. (2021a), the labour related challenge of ‘difficulty in harvesting’ is due to the fact that most farmers in Uganda use the hand hoe to dig up the pods regardless of the time of harvest or the soil conditions. In many parts of SSA however, difficulty in harvesting is suggested to arise mostly from the timing of harvest with respect to soil moisture conditions and maturity stage (NRC, 2006). When the soil is moist and soft enough and the crop is at an early maturity stage (yellowing of leaves), the plants can easily be pulled out (NRC, 2006). However, when the soil is dry and the crop is at a late maturity stage (with dry stems and senesced leaves), the plants have to be dug out and pods collected individually, hence making it more labour   intensive    (Obura   et  al.,  2021a;  NRC,  2006). Despite all these challenges, persistent farmers often devise means to address most of them, hence, continue to grow BN for reasons such as food security and seed maintenance discussed under ‘scale and trend of Bambaranut production’. The mitigation measures for difficulty in seed access for example include saving own seeds, buying in the local market and obtaining  from  the neighbor (Table 6). On the other hand, the involvement of most or all family members in harvesting reduces the tediousness of harvesting. Although limited market features prominently among the challenges, the issue perhaps relates more to market for bulk sale of dry grains or seeds rather than no market at all, because the majority of respondents who grow the crop admit that there is always market for the fresh boiled snack within the village. They therefore plant small acreages mainly for home consumption and sell in the local market to ensure they meet the relatively low demand (Table 6). Interestingly, the problem of ‘hard to cook’ (HTC) that ranks highly among challenges in other parts of SSA for example in Zimbabwe (Mubaiwa et al., 2017), Nigeria (Aviara et al., 2013) and Ghana (Berchie et al., 2010b) apparently was not as serious in Uganda (Figure 6). The explanation for this can be found in the ways the crop is mostly consumed, that is, fresh boiled snack and a local dish known as ‘dek ngor’/’emagire’, and the preparation methods prior to cooking namely decortication and soaking (in ‘utilization of Bambaranut’). Decortication removes the hard seed coat implicated in HTC, while soaking softens it and allows prior permeation of water into the seeds, thereby easing the cooking (Mubaiwa et al., 2017). The root cause of all these challenges is the fact that BN has for long remained an ‘orphan’ crop in the country, languishing outside the bounds of research and development, restricted to confines of communities. Thus, there has hardly been any crop improvement or commodity development efforts accorded to it, despite its potential in food and nutrition security and resilience agriculture (Mayes et al., 2019; Mubaiwa et al., 2018a; NRC, 2006). Across most production regions of SSA,  BN is faced with similar challenges which have also been attributed to the status of the crop as a neglected and an underutilised species (Mubaiwa et al., 2017; Aviara et al., 2013; Adzawla et al., 2016b; Berchie et al., 2010b; NRC, 2006; Azam-Ali et al., 2001). Similar mitigation measures have also been reported for the most common challenges for example, saving own seeds or buying in the local market in an effort to ensure seed availability is a practice that is common among BN farmers in Ghana (Berchie et al., 2010b). Taken together, the self driven efforts by BN farmers to overcome numerous obstacles and continue production of BN with minimal resources point towards resilience and hope for agricultural sutainability.

Opportunities for improving production and utilization of Bambaranut in Uganda

Promising trends in production and seed management

Production figures in Uganda revealed that quantities harvested and sold generally increased within a three year period from 2016 to 2018 (Table 2). The same period saw a decrease in the number of farmers not producing the crop with 97% of this group willing to re-engage in growing the crop for reasons mentioned earlier. These scenarios are suggestive of a steady increase in the area under and quantity of BN that is likely to be produced in subsequent years. Further backing to the increase is the promising engagement of the younger generation (21-40 years) and the encouraging involvement of men (38% of all BN farmers in the two regions) in BN production and utilization. While this may be considered a relatively low percentage for men’s involvement, it is higher than what exists elsewhere in SSA e.g., in western Niger where the proportion is 95% and 5% respectively for women and men (Ibrahim et. al., 2018). The involvement of the youth and fair participation of the men provides a wider platform for the production and utilization of BN in those communities. In addition, the existing practices, though not ‘standard’, have demonstrated an impressive level of effectiveness. Bambaranut farmers consistently carry out practices such as earthing up and proper timing of harvest to ensure good yields. This further extends to seed management whereby quality assurance is observed at multiple stages in the seed cycle; selection, threshing, sorting and storage (Obura et al., 2021a). Seed samples provided by farmers during this study exhibited relatively high quality in laboratory tests (Obura et al., 2021a).  In summary, BN is produced on a relatively small scale, but there is a promising trend of increase that is likely to be sustained by a young generation of farmers; BN cropping  practices are traditional, but are relatively effective with a lot of opportunities for improvement;  only  a  small  quantity  of BN seed is available, but is of good quality. This therefore means that improving on these practices will be relatively straightforward and can provide an entry point for building resilience and promoting agricultural sustainability within the communities involved.

Beyond the farming communities

Research to build and consolidate basic information on Bambaranut: Quite encouraging research has been conducted on BN in such areas of agronomy (Chai et al., 2016; Mabhaudhi, 2013; Collinson et al., 1996); seed quality (Mandizvo and Odindo, 2019; Chibarabada et al., 2015; Chibarabada et al., 2014); nutritional characteristics (Mubaiwa et al., 2018b; Yao et al., 2015; Okpuzor et. al., 2010); and socio-economic aspects (Ibrahim et al., 2018; Mubaiwa et al., 2018a; Hillocks et al., 2012; Berchie et al., 2010b) among others. While these are still not considered to be comprehensive work on the crop in comparison to research on other grain legumes in SSA, they are in stark contrast to the efforts in Uganda where there has been extremely limited documented formal research on BN (Obura et al., 2021a). There is thus a huge opportunity for researchers in Uganda to generate extensive information on BN that will lead to better understanding and appreciation of the crop among farmers, research institutions, development partners and government agencies. This will in turn improve the crop’s relatively unknown reputation as one with vast potential for food security and community resilience. Priority areas of research will include collection and documentation of all available landraces in the country, more detailed and specific surveys e.g. targeting farmers preferences for landraces; agronomic performance of landraces of Uganda; survey to identify and characterise Bambaranut pests and diseases in Uganda; developing pests and diseases management strategies; variety development and crop improvement, developing value chains for different Bambaranut products in the country.

Germplasm management: Several landraces exist in the country (at least 14 were encountered during this survey). However, only three are under maintenance at the National Gene Bank of Uganda (NGBU) (NARO, 2022) while a few more are perhaps being maintained at the National Semi Arid Resources Research Institute (NaSARRI). It is clear, therefore, that there is need for a rigorous collection targeting the entire country, of all the available landraces. These and the already identified types should undergo proper documentation and management to ensure their availability if and when needed by breeders for varietal development or breeding research, community seed producers for seed production and maintenance, and institutions of learning for  learning purposes. For good purpose however, the International Institute of Tropical  Agriculture (IITA), Nigeria (1815), the Institute  of  Research  for  Development   (IRD),   France (1000), and The Southern African Development Community (SADC) (unspecified) have huge collections of BN germplasm that are being maintained in their gene banks (Aliyu et al., 2016). Most, if not all the materials encountered in this baseline survey or maintained at NaSARRI and the NGBU are likely part of the collections mentioned above. The relevance of such huge collections become clear when BN improvement programs are initiated in the country that require a pool of diverse germplasm, when there is need for introductions of new types to the country’s current pool of germplasm and once various research activities are to be undertaken to consolidate information on the crop.

Seed production and maintenance: As research goes on in the various aspects of the crop, a seed production scheme can in the meantime be initiated to address the current seed gap. Seeds of preferred/commonly cultivated types in each region should be maintained and limited quantities produced on demand to serve the interest of groups and/or individuals in need of seeds that may not be readily available in their areas. Research institutes in the predominant production areas could take the lead and engage local seed business groups (LSBs) to provide arguably the most suitable pathway through which a functional seed system can be achieved (Mastenbroek, 2015). Already this model has shown great promise for both commercial varieties of ‘priority’ crops and traditional food crops in those regions (Mastenbroek et al., 2021; Mastenbroek, 2015). This will ensure consistent availability of seeds for planting, hence, sustained production and consumption. The obvious challenge with this model is the resources needed for maintenance and production of the seeds at the research stations or by the community and/or LSBs. In the very beginning, it will take the dedication and sacrifice of legumes research scientists in those institutes to allocate some minimal resources to BN and carry it along their core legumes research activities. 

Community sensitization: Climate change and climate variability and their impacts, adaptation and mitigation and community involvement should be emphasized. This can be through public and on farm programs led by relevant government institutions, development organizations with food security programs and other organizations that are within or work closely with communities.