Socio demographic characteristics of respondents
In total, 500 pigeonpea producing households including 190 in the Guinean zone, 200 in Sudano-Guinean zone and 110 in the Sudanian zone were surveyed. Pigeonpea farmers participated in the surveys were from 21 to 76 years old with an average of 45.9±9.2 years old. The majority (62.4%) of pigoenpea farmers were men (62.4%) and illiterate (43.4%), while 31.6% and 25% were found to have primary and secondary levels of education, respectively. The average household size was 6.4±2.1 members (ranging from 3 to 11 members). The years of experience was 15±8 years, on average (Table 2).
Significant differences in surveyed pigeonpea farmers’ ages were observed even across ecological zones. On average, farmers in the Guinean zone are older (48.7 years against 44 years) and more experienced than Sudano-Guinean zone farmers (18.4 years of experience against 16.5). The number of farmers with no education, primary and secondary level of education varied between ecological zones.
Local nomenclature
Across the thirteen sociolinguistic groups surveyed, 50 different pigonpea local names were recorded in the local dialects. In reference to the various vernacular names identified, the generic name of pigeonpea varied according to sociolinguistic group and ecological zones (Table 3).
In the Guinean and Sudano-Guinean zones, pigeonpea is called Hounkoun, Kloué or Klouékoun referring to cowpea, by farmers belonging to Fon and Mahi sociolinguistic groups while in the Guinean and Sudanian zones, pigeonpea is called, Otili in reference to a pod-producing tree, by farmers belonging to Nago and Dendi sociolinguistic groups. However, Bariba and Peulh sociolinguistic groups designated pigeonpea by Wotiri in reference to a pod-producing erected tree. Moreover, in the Guinean zone, farmers belonging to Holly and Yoruba sociolinguistic groups designated pigeonpea by Otini. Pigeonpea is called Ekloui or Kloui by Adja sociolinguistic group. In Sudano-Guinean zone, pigeonpea is called Colo (meaning is unknown to farmers) by Idaasha sociolinguistic group while pigeonpea is called Tissi Tounan and Itoun by Biali and Somba sociolinguistic groups respectively, referring to cowpea.
Folk taxonomy
In the study area, farmers were using 5 different criteria to designate pigeonpea. The great majority of names (90.7%) given to pigeonpea have a meaning. More than half of pigeonpea vernacular names correspond to the morphological aspect (71%) of seeds. This includes seed coat colour (85.5%), seed coat and eyes colour (9.2%), seed size (1.3%), seed coat colour and size (4%). Plant type (3.7%), seed origin (8.4%), vegetative cycle (10.3%) and in reference to cowpea (3.7%) were also among criteria used by farmers to name pigeonpea (Table 4).
The folk taxonomy of pigeonpea has a hierarchical structure with two hierarchy levels as found in several sociolinguistic groups (Adja, Bariba, Fon, Holly, Idaasha, Mahi, Nago, Peuhl and Yorouba). For example, in the Adja sociolinguistic group, the generic name of pigeonpea Ekloui or Kloui is subdivided into 5 infra-specific pigeonpea taxa (Ekloui djou, Ekloui koudji, Ekloui ri, Ekloui wlanwlan, Ekloui wliwlito). In the Fon sociolinguistic group, the generic name of pigeonpea Klouékoun is subdivided into 6 infra-specific pigeonpea taxa (Klouékoun vôvô, Klouékoun wéwé, Klouékoun wéwé tété, Klouékoun wéwé noukoun vôvô, Klouékoun wéwé noukoun wiwi, Klouékoun wlanwlan). While in the Bariba sociolinguistic group, the generic name of pigeonpea Wotiri is subdivided into 4 infra-specific pigeonpea taxa (Wotiri gbika, Wotiri goukorou, Wotiri wonka, Wotiri souan).
Diversity of cultivated pigeonpea landraces
Based on seed characteristics, fifteen pigeonpea landraces were identified in the study area (Figure 2). At village level, the number of pigeonpea landraces ranged from 1 to 5 with an average of 2.7 ± 1. The highest number of landraces (5) per village was reported at Ouèssènè in the department of Alibori. At the household level, the number of pigeonpea landraces held by farmers ranged from 1 to 3 with an average of 1.3 ± 0.5. Specifically, 72.2%, 27.6% and 0.2% of the farmers cultivated 1, 2 and 3 landraces respectively. The highest number of landraces (3) per household was reported at Ouèssènè in the department of Alibori and maintained by only one farmer. The Sudano-Guinean zone contained the highest number of landraces followed by the Guinean and Sudanian zones (11, 9 and 7 landraces respectively) while the highest number of landraces (5) per village and per household (3) was recorded in the Sudanian zone.
Distribution and extent of pigeonpea landraces
Within each ecological zone, pigeonpea production was limited to specific districts and departments. In the Guinean zone, the production was restricted to the districts of Adja-Ouèrè, Kétou and Pobè in the department of Plateau, and the districts of Aplahoué, Klouékanmè and Lalo in the department of Couffo. In the Sudano-Guinean zone, pigeonpea is cultivated in the districts of Dassa-Zoumè, Ouèssè, Savalou and Savè in the department of Collines, and the districts of Covè, Djidja, Zakpota and Zangnannado in the department of Zou. Lastly, in the Sudanian zone, pigeonpea is cultivated in the districts of Bembèrèkè and Kalalé in the department of Borgou, and in the district of Gogounou in the department of Alibori.
The Four Squares Analysis revealed that in the Guinean zone, among the 9 landraces recorded, 1 (Klouékoun wéwé noukoun vôvô (Mahi and Fon sociolinguistic groups)) is cultivated by many households on a large area, 1 (Otili founfoun kékélé (Idaasha sociolinguistic group)) by few households on large area while the 7 remaining ((Ekloui djou (Adja sociolinguistic group), Wlétchivé kloui (Adja sociolinguistic group), Carder ekloui (Adja sociolinguistic group), Otili founfoun lakoun (Idaasha sociolinguistic group), Klouékoun wéwé tété (Mahi sociolinguistic group), Otili kpoukpa (Nago sociolinguistic group) and Klouékoun vôvô (Fon and Mahi sociolinguistic groups)) are produced by few households on a small area.
In the Sudano-Guinean zone, Klouékoun wéwé nounkoun wiwi (Mahi and Fon sociolinguistic groups) is cultivated by many households on a large area, Klouékoun wéwé tété (Mahi sociolinguistic group) and Otili founfoun kékélé (Idaasha sociolinguistic group) are cultivated by few households on a large area, and Wlétchivé kloui (Adja sociolinguistic group) and Klouékoun wlanwlan (Fon sociolinguistic group) by many households on a small area. Klouékoun wéwé nounkoun wiwi (Mahi and Fon sociolinguistic groups), Otini kpoukpa (Holly sociolinguistic group), Colo kpikpa (Idaasha sociolinguistic group), Otili founfoun lakoun (Idaasha sociolinguistic group), Otili kpoukpa (Nago sociolinguistic group) and Klouékoun vôvô (Fon and Mahi sociolinguistic groups) are cultivated by few households on a small area.
In the Sudanian zone, 2 landraces ((Klouékoun wéwé nounkoun wiwi (Mahi and Fon sociolinguistic groups) and Otili founfoun kékélé (Idaasha sociolinguistic group)) are cultivated by many households on a large area while 1 landrace ((Klouékoun wlanwlan (Fon sociolinguistic group)) is cultivated by few households on a large area. 4 landraces ((Ekloui djou (Adja sociolinguistic group), Wotiri wonka (Bariba sociolinguistic group), Wotiri souan (Bariba sociolinguistic group) and Klouékoun vôvô (Fon and Mahi sociolinguistic groups)) are cultivated by few households on a small area. Thus, in the Guinean zone, 7 landraces are under threat of disappearance, 6 in the Sudano-Guinean zone versus 4 in the Sudanian zone. In areas where landraces are threatened, the frequency of disappearance varied between 50 and 100% (Table 5).
At on-farm level, the landraces distribution analysis revealed that Otini kpoukpa (Holly sociolinguistic group), Colo kpikpa (Idaasha sociolinguistic group) and Klouékoun wéwé nounkoun wiwi (Mahi and Fon sociolinguistic groups) were specific to the Sudano-Guinean zone; Wotiri souan (Bariba sociolinguistic group) and Wotiri wonka (Bariba sociolinguistic group) specific to the Sudanian zone while Carder ekloui (Adja sociolinguistic group) was specific to the Guinean zone. Klouékoun wéwé nounkoun wiwi (Mahi and Fon sociolinguistic groups), Otili founfoun kékélé (Idaasha sociolinguistic group) and Klouékoun vôvô (Fon and Mahi sociolinguistic groups) were cosmopolitan for the three ecological zones. Landraces named Wlétchivé kloui (Adja sociolinguistic group), Otili founfoun lakoun (Idaasha sociolinguistic group), Klouékoun wéwé tété (Mahi sociolinguistic group) and Otili kpoukpa (Nago sociolinguistic group) were present in the Guinean and Sudano-Guinean zones, Ekloui djou (Adja sociolinguistic group) in the Guinean and Sudanian zones while Klouékoun wlanwlan (Fon sociolinguistic group) was present in the Sudano-Guinean and Sudanian zones.
Reasons for pigeonpea production and use category
Our study has revealed that pigeonpea produced for three main reasons depending on the ecological zones (Table 6). In the Guinean and Sudano-Guinean zones, nutritional value is the main motivation while in the Sudanian zone, the land fertilizing power is the main motivation. The third reason is the market value.
The different pigeonpea use categories were mainly concentrated on grains. Based on their fidelity level, pigeonpea is used more in medicine in the Guinean (FL = 19.5%) and Sudanian (FL = 23.9%) zones. According to famers, boiled leaves are administered orally to treat malaria. Also, the decoction of the leaves is used in baths to treat measles and is also used as an antibiotic to treat mouth sores or tooth decay. The roots, when chewed, prevents the rise of snake venom, in the case of snake bite.
The use of pigeonpea grains as an offering for food or symbolic purposes and in sacrifice to divinity to request for more yield the following season is specific to the Sudano-Guinean zone and only restricted to Holly and Nago sociolinguistic groups. While grain processing into donuts is specific to Guinean (FL = 4.3%) and Sudano-Guinean (FL = 2%) zones and only restricted to Holly and Adja sociolinguistic groups. In these zones, pigeonpeas are roasted and ground to flour to sprinkle in sauces as a nutritional supplement by farmers belonging to Holly sociolinguistic group or to make donuts by farmers belonging to Adja sociolinguistic group. Consumption, weeds control and land fertilization are common to all three ecological zones (Table 6).
Cultural practices
Pigeonpea was considered as an annual plant by most of the surveyed farmers (93.2%). Only 6.2% of farmers considered this legume as a perennial plant. For the latter, the plant is left in the fields and is harvested the following year. The main pigeonpea farming activities included: ploughing, sowing, weeds control, pod harvest, pod plugging and winnowing. Seeding and weeds control were practiced by all the farmers. Pigeonpea is sown between April and June (73.6%) by intercropping with other seasonal crops (82.8%) or in pure stand (17.2%). Three sources of labour were observed. For farming activities, 13.2% of farmers used family labour, 73% combined family and friends labour while 13.8% used a combination of family, friends and jobber labour (Table 7).
The activity of land fertilization was never practiced by farmers included in this study while only 14% of farmers included in this study used pesticide. The average grain yield in farmers’ fields was estimated at 553.4±36.3 kg/ha. According to the farmers, during the three last years, Sudano-Guinean zone was the largest cropping area followed by the Guinean zone while farmers in the Sudanian zone produced pigeonpea on a small cropping area (Table 7). Sowing was actively done between April - June in the Guinean and Sudano-Guinean zones (97.9% and 91% respectively) whereas it was actively done in June, July and August in the Sudanian zone (68.2%). Intercropping with other seasonal crops such as maize and millet was specific to the Guinean (100%) and Sudano-Guinean (98.5%) zones while pigeonpea was cultivated mostly in pure stand in the Sudanian zone (75.4%).
Family and friends were the main source of labour for various farming activities in the Guinean and Sudano-Guinean zones (87.9% and 61.5% respectively) while family members (49.3%) were the main source of labour in the Sudanian zone. Our results revealed that the average yield of pigeonpea in the Sudanian zone is lower (522.3 ± 44kg/ha) than that of the Guinean and Sudano-Guinean zones (557.5 ± 15.9 kg/ha and 566.6 ± 35.8 kg/ha respectively).
Seed system
Different sources of seeds were mentioned by farmers. Previous harvest (60.2%) is the main source of seeds. Other sources are borrowing of seeds from friends (22%) and seeds purchased from the local market (17.8%). After each harvest, 67.8% of farmers stored seeds until scarcity at market or for the following season while 32.2% of them sold seeds in local markets. The comparison of the seed systems between ecological zones revealed that previous harvest is the main source of seeds in the Guinean and Sudano-Guinean zones (70% and 62.9% respectively) and borrowing of seeds from friends is the main source (50.4%) in the Sudanian zone. After each harvest, farmers stored more grains in the Guinean and Sudano-Guinean zones (70% and 84% respectively) while more grain was immediately sold in the Sudanian zone (65.5%) (Table 7).
Pigeonpea production constraints
In total, 10 constraints were identified as major bottleneck in pigeonpea production. Among which, the long vegetative cycle, pests, diseases and rainfall irregularity were considered as the major constraints (Table 8). According to the farmers’ descriptions, low productivity ranked seventh among the constraints followed by the sensitivity to storage insects. All these constraints have been reported in the three ecological zones. However, their relative importance varied from one zone to another. The most important constraint in the Guinean and Sudano-Guinean zones was the long vegetative cycle. Sensitivity to pests and diseases ranked second. In the Sudanian zone, pests and diseases ranked as the most important constraint and soil poverty was second (Table 8).
Incidence of pests on pigeonpea yield and control methods
The incidence of pests and diseases on farmers’ field was as follows: low in the Guinean and Sudano-Guinean zones (52.6% and 42.5% respectively), high in the Sudanian zone (81.8%) (Table 9). As a result, farmers reported growth retardation and damage to flowers or pods respectively. A pest control method was only reported in the Sudanian zone (63.7%). Three reasons justified the non-control of pests: high price of pesticides (49.6%), risk of intoxication (29.6%) and lack of sprayers (20.8%).
Evolution of pigeonpea production in Benin
Overall, majority of the farmers (69.4%) reported a decrease of pigeonpea production in Benin. This downward trend was observed for the Guinean and Sudano-Guinean zones (75.79% and 85.5% respectively). In these zones, the decrease in cropping area is highly significant (p ˂ 0.001). The average cropping area was 0.9 ±0.2 ha in 2015, 0.8 ± 0.1 ha in 2016 and 0.5 ±0.1 ha in 2017 in the Guinean zone (Table 7). Similarly, in the Sudano-Guinean zone, average cropping area was 1.3 ± 0.8 ha in 2015, 0.9 ± 0.4 ha in 2016, 0.7 ± 0.3 ha in 2017 (Table 7). In contrast, in the Sudanian zone, pigeonpea cultivation is increasing (70.91%). In this zone, the increase of cropping area is highly significant (p˂0.001). The average cropping area was 0.3 ± 0.1 ha in 2015, 0.4 ± 0.1 ha in 2016 and 0.4 ± 0.1 ha in 2017 (Table 7). This increase is due to the fertilizing power of the plant (89.1 %) and weed control (10.9%).
Farmers’ preference criteria of pigeonpea
Throughout the study, 11 criteria depending on the ecological zones and different sociolinguistic groups highlighted the choice of pigeonpea varieties to be cultivated by farmers. Farmers perceived precocity, resistance to pests and diseases, short cooking time, adaptability to any type of soil, good taste, and high productivity as the most important preferred traits (Table 10). In the Guinean and Sudano-Guinean zones farmers had a strong preference for early maturing (precocity) and resistant to pests and diseases pigeonpea varieties; while in the Sudanian zone, farmers preferred pigeonpea varieties that were resistant to pests and diseases and adaptable to any type of soil (Table 10). Precocity appeared high on the list of criteria for all sociolinguistic groups except Nago sociolinguistic group for whom adaptability to any type of soil was the first criterion. Farmers belonging to the Bariba sociolinguistic group preferred varieties that mature early, are resistant to pests and diseases, have short a cooking time, show adaptability to any type of soil and have good taste (Table 11). In addition to Bariba sociolinguistic group’s preferred traits, farmers belonging to Boo sociolinguistic group showed strong tendency towards pigeonpea varieties that are cultivable at any time of the year and resistant to storage insects. Dendi sociolinguistic group preferred varieties with high productivity and cultivable at any time of the year and Peuhl sociolinguistic group preferred highly productive and resistant to storage insects pigeonpea varieties. Precocity, resistance to pests and diseases, short cooking time and adaptability to any type of soil were farmers belonging to the Yoruba sociolinguistic group preferred traits.
Participatory evaluation of pigeonpea landrace grown in Benin
Our results revealed that none of the landraces identified simultaneously in the three ecological zones is performing for a given character simultaneously in the three ecological zones (Table 12). Moreover, no landrace is performing simultaneously for all 5 evaluated traits. Nevertheless, Carder ekloui (Adja sociolinguistic group) specific to the Guinean zone combined 4 good performances (high productivity, short cooking time, resistance to pests and diseases, and resistance to storage insects). Carder ekloui (Adja sociolinguistic group) and Otili founfoun kékélé (Idaasha sociolinguistic group) showed high productivity in the Guinean and Sudano-Guinean zones but showed low productivity in the Sudanian zone however, these two landraces, showed resistance to pests and diseases. Klouékoun vôvô (Fon and Mahi sociolinguistic groups) showed high productivity, short cooking time, resistance to pests and diseases, resistance to storage insects and short vegetative cycle in the Guinean and Sudano-Guinean zone, but showed low productivity and susceptibility to pests and diseases in the Sudanian zone (Table 12).