Little attention has been given to assessing the medicinal plant species in home gardens. Many studies in the past have focused on the socio-economic aspects of home gardens, their structure and composition, organization as well as their nutritional importance with little attention to the medicinal use. This Study seeks to assess the medicinal flora species that are found in home gardens in Benue State. Medicinal plants have played an important role throughout the world in treating and preventing human diseases. Studying medicinal plants helps to understand plant toxicity and protect human and animals from natural poisons. It is imperative to identify and document medicinal plants found in home gardens in Benue State in order to encourage conservation and management of the plant species that have the potency of curing ailments. This research seeks also to identify the ailments/diseases for which home garden medicinal plants are used for treatment. About 74 plant species were identified in Home gardens in Benue State. Home gardens in Vandeikya and Katsina-ala (zone A) had more diverse species with species diversity index of 0.9691 with a total of 67 plant species. Jaccard’s Similarity coefficient revealed that home gardens in zone B (Gwer west and Gwer East) had the highest percentage Similarity of 91.3%. Descriptive statistics revealed that 22 plant species are the most frequently used medicinal plants. Home gardens in Benue State have diverse species of plants which have numerous uses ranging from their use as food, shade and medicine.

Keywords: Home-garden, Medicinal plants, Species diversity, Ailments, Similarity

INTRODUCTION

Home-gardens involve the management of multipurpose trees, shrubs, annual and perennial crops, herbs and medicinal plants, birds and animals on the same land unit in a spatial or temporal sequence [1]. It is a traditional land use practice carried out around a homestead consisting of several species of plants that are grown and maintained by the family members with the primary objective of fulfilling the family’s consumption needs [2]. They are production systems of diverse crop plants, which are easily accessible and adjacent to household [3].

Home gardens represent land use systems involving deliberate management of multipurpose trees and shrubs in intimate association with annual and perennial agricultural crops and invariably livestock within the compounds of individual houses [4]. For decades home gardens have shown to be significant to rural inhabitants by providing a wide range of useful products such as fruits, vegetables, medicine and building materials [5]. Several studies have emphasized that home gardens are diverse agro-forestry systems and regard them as important ex situ conservation sites. Worldwide, home gardens are a community’s most adaptable and accessible land resources and important components in reducing vulnerability and ensuring food security [6]. Forest resources such as edible fruits and medicinal plants are harvested from home gardens. Worldwide, growing ethno botanically useful plant species in home gardens has a long tradition in various cultural groups. Growing a number of plant species together in home gardens do not only deal with making resources available for food and medicine but also reveal invisible social mechanisms and related resilience strategies by avoiding risk and reducing vulnerability as may be noticed generally in single crop cultivation [6]. Home gardens consist of a mixture of cultivated fruit trees, medicinal plants, spices, firewood and sometimes also forage crops. Home gardens have the potential to contribute towards increasing food production, reducing  malnutrition  and ailments  in  tropical countries. It has been a way of life for centuries and is still critical to the local subsistence of economy and food security.

The emergence of new diseases and re-emergence of old diseases has been a great challenge in the use of orthodox medicine. At the moment, the remedies remain elusive. However, it has been proved that higher plants have the potential to provide solutions to these problems.

Pharmaceutical drugs are seen increasingly as expensive and dangerous, yet herbal remedies are seen as less expensive and less toxic. Almost every pharmaceutical drug has side effects. People in tropical countries like Nigeria are increasingly willing to self-treat their medical needs by using medicinal plants and herbal preparations particularly for the treatment of illnesses such as arthritis, diabetes, hepatitis, typhoid, yellow fever, cancer and stroke. Successful management of such ailments is elusive with pharmaceutical drugs. A lot of pathogens have proved resistant to conventional antibiotics [7]. People who suffer such maladies are turning to medicinal plants as alternative for treatments [8]. Many of these herbs are found in home gardens. It is imperative to identify and document the medicinal plants found in and around home gardens in Benue State in order to encourage conservation and management of these wonderful plant species that have the potential of curing ailments. Currently pharmaceutical companies have demonstrated interest in investigating higher plants as sources of drugs. In Brazil, some plants were screened against Staphylococcus aureus and Enteroccocus fecalis. These microbes are known to cause surgical and post-surgical ailments as well as medical complications in humans. The plants were found to have antimicrobial effect against the microbes [7]. Medicinal plants remains an integral part of human life through the compounds extracted from plants and specific plant parts are worthy of further investigations for their use as potent sources of medicine.

MATERIALS AND METHOD

Study area: Benue State

Benue State is located in the middle belt region of Nigeria with a population of about 4,253,641. The State has an average population density of 99 persons per km². It is inhabited predominantly by the Tiv and Idoma people, who speak the Tiv language and Idoma, respectively. There are other ethnic groups, including the Igede, Etulo, Akweya and Nyifon [9]. The capital of Benue is Makurdi. It is a rich agricultural region. Benue State is named after the Benue River and was formed from the former Benue-Plateau State in 1976. Benue State is the 9^th most populous State in Nigeria.

Its geographic coordinates are longitude 7°47' and 10°0' E. Latitude 6°25' and 8°8' N; and shares boundaries with five other states namely: Nasarawa State to the north, Taraba State to the east, Cross-River State to the south, Enugu State to the south-west and Kogi State to the west. The state also shares a common boundary with the Republic of Cameroon on the south-east. Benue occupies a landmass of 34,059 km². The State experiences two distinct seasons; the wet season and dry season. Temperatures fluctuate between 21-37°C (Figure 1).

METHODOLOGY

Two local government areas from each of the three (3) geopolitical zones of the State were randomly selected for the study. The local government areas are Vandeikya and Katsina-Ala (Zone A), Gwer west and Gwer-East (Zone B), Ogbadibo, Oju (Zone C). Four (4) Council wards from each Local Government Area were purposively selected for ease of accessibility. In each Council ward, Five (5) compounds with home gardens were visited, making a total of twenty (20) home gardens from each Local Government Area. This means forty (40) compounds with home gardens were visited in each geopolitical zone. Altogether a total of one hundred and twenty (120) home gardens were visited covering the three (3) geopolitical zones. Data were collected by walking through the home gardens and making careful identifications of the plants, listing the plant species and the medicinal uses of such plants. Interviews with home garden owners were conducted using a semi-structured questionnaire based on methodologies. Home garden owners were asked the following questions in order to obtain a list of medicinal plants found in their home gardens:

   i. What species of plants in your home gardens are used for medicinal purposes?

  ii. What type of sickness or disease are they used for treatment?

iii.  What part of the plant is used for medicine?

iv.  Which plant species in your home garden is mostly used for medicine?

Five (5) traditional medicine practitioners were also interviewed in each council ward. The traditional medicine practitioners were selected based on how they are considered by their communities as very knowledgeable about medicinal plants. During the interview, the traditional medicine practitioners were allowed to discuss what species of plants in their home-gardens are medicinal, what kind of diseases the plants are used for treatment, what part of the plant is used (stem, roots and leaves).

During the visit to each home garden, the house heads were interviewed to know which among the home garden flora, are medicinal, the type of sickness that home garden medicinal plants cure and what part of the plant is used for treatment. To know which home garden medicinal plants are most frequently used in treating ailments?

After data collection, data were subjected to simple descriptive statistics like frequency and percentage to determine the frequency of use of the medicinal plants. The most frequently used medicinal plants in home gardens in Benue State were then determined.

DATA ANALYSIS

Frequency, percentage and tabular presentations were used to estimate the relative abundance of each species. Simpson Diversity index was used to test the diversity of flora species in home gardens in Benue State. Jaccard’s similarity coefficient (JSC) was used for comparing home garden’s plant species in two randomly selected local government areas in each geopolitical zone of the State.

Where,

a=number of species not found in the study area A

b=number of species not found in the study area B

c=number of species common in both Areas

Simpson diversity Index,

Where,

n=number of individuals of each species

N=Total number of individuals of all species

PRESENTATION OF RESULTS

Table 1 shows the personal attributes of home garden owners. Most of the respondents were males with the percentage of 71.67% while 28.33% were females. Majority of the respondents were within the age range of 50 years and above (50.83%) followed by the age range of between 40-50 years while young people were within the age range of 18-28 years with a percentage of 0.83%. Most of the home garden owners were married (81.70%), widowed (17.50%) while single (0.83%). A greater percentage of the respondents (33.33%) had household size of more than 12 followed by a family size of 7-9 with a percentage of 30.83%. The least family size 1-2 had a percentage of 5.83%. 42.50% of the respondents did not have formal education. 0.83% had degree or HND. 49.17% of the respondents had an annual income of more than ₦ 150, 000.00. The respondents with the least level of income had a percentage of 8.33%.

Table 4 shows that the composition of home gardens across the three Geo-political zones varies. Zone A with 67 Plant species was the most diverse plant with Simpson index of 0.9691 followed by Zone C with 46 Plant species and index of 0.9664 and then Zone B (0.9647) with 46 species.

Table 5 shows that very high similarity among plant species in home gardens in Zone B Local government areas of Benue. A jaccard coefficient of 0.91 means plant species in home gardens in Zone B were 91.3% similar. Home gardens in Local government areas of Zone C had a Jaccard similarity coefficient of 0.64. That means the plant species in Zone C were 64.0% similar. Jaccard’s similarity coefficient 0.52 means the home gardens in Zone A local government areas were 52.2% similar (Table 6).

DISCUSSION

Personal attributes of respondents by sex and age

Table 1 shows that majority of the home garden owners were men (71.67%), women were 28.33%. This implies that the household heads of the compounds visited were mostly men. This is similar to the findings of Melese and Fitamo [10]. Hence men are the heads of the households; they take major decisions in the family and therefore determine what should be planted around their home. This indicates that the choice of plant species (especially trees) grown or conserved in home gardens in Benue State is determined mostly by men. The choice of such plant species is associated with their use as food consumed in everyday life and the use of certain plant species to treat ailments. The choice of such plant species is related to the importance attributed to the plants. This agrees with the findings of others which states that women play significant role in the maintenance of home gardens but the establishment is solely that of men. However the choice of food crops grown in home gardens is usually determined by women. In terms of tree species, it does not apply. Only households with widows (17.50%) have such privilege. In terms of traditional medicine practice, Table 2 shows that 70.83% of the 120 traditional medicine practitioners who were interviewed were men. While 29.17% were women. The result shows that men were more involved in the practice of plant medicine than women.

Majority of the respondents (50.83%) were in age group of 50 years and above, 39.17% in the age group 40-50 years and a few of them were in the age group of 29-39 years (9.17%). 0.83% was in the age group 18-28 years. This underscores that home garden owners were mostly the elderly people. This agrees with the findings of Agbogidi and Adolor [11] that majority of those involved in home gardening activities are elderly household members who often remain faithful to the conservation and maintenance of useful plants they have inherited from prior generations and Regassa [12] who reported that old aged people are mostly involved in the management of home garden. The result is also similar to the findings of Melese and Fitamo [10]. This result is also contrary to the report of some others which stated that majority of the home garden owners were young and agile.

Marital status of respondents

From Table 1, majority of the respondents were married (81.70%). Few were widowed (17.50%) and single (0.83%). This explains that home gardens in Benue State are mostly maintained by married people. This is similar to the report which stated that a greater percentage of the respondents were married. This shows that the respondents were matured adults with marital responsibilities; hence their involvement in the management of home gardens to make ends meet in the family.

Household size of respondents

Out of the 120 households visited, the least family size was in the range of 1-2 with 5.83% while the biggest family size was in the range of 12 and above with 33.33% followed by the family size within the range of 7-9 with 30.83%. The family size with the range of 4-6 had a percentage of 19.17%, family size within the range of 10-12 had 10.83%. This implies that different family sizes are dependent on home gardens for the sustenance of their families. This could be the benefits derived in form of food, income and medicine from the multipurpose trees. This is similar to the findings of Amanda et al. [13] that home garden plants (edible and medicinal plants) contribute largely to the family subsistence.

Educational status of respondents

Out of 120 respondents, 42.50% of the respondents had no formal education, 16.67% had primary education and 24.17% had secondary education, 15.83% had NCE and Diploma, while 0.83% had Degree. This implies that formal education is still low in rural areas in Benue State. Knowledge of the home garden owners affects the development of economically viable and ecologically sustainable home garden with regards to plant conservation [14].

Floristic composition and distribution of home garden plants in Benue state

A Total of 74 plant species belonging to 40 families were identified (Table 3). Not all the plants were grown by the home garden owners. Some plants established naturally in the home gardens but some are maintained by the home garden owners because of the use value. The family Fabaceae had the highest number of eight (8) species. This is similar to the report by Regassa [12]. Followed by Anacardiaceae, Malvaceae and Arecaceae had 4 species each. The families Eurphorbiaceae and Rutaceae had 3 species pieces each. Ten (10) Families had 2 species each. This is similar to the findings of Melese and Fitamo [10]. Twenty-eight (28) families had 1 species each. Table 2 shows the distribution of home garden plant species according to the three major tribes in Benue State. The home gardens in Benue State consist of both cultivated and non-cultivated plants. Some plants were found growing naturally in home gardens. They are maintained by home garden owners because of the several uses such plants provide for them. Some plant species like Chasmanthera dependens, Maytenus senegalensis, Spermacoce octodon were found being cultivated in some home gardens in Benue State. While certain plants were found growing in one home garden and were never found growing in another even among home gardens within the same community. They are unique plants which vary across the six local government areas that were covered in the study. From the result of the study, these unique plant species include Phoenix dactylifera (found only in Vandeikya), Chrysophyllum albidum (Only in Ogbadibo), Pterocarpus santalinoides (only in Oju), Theobroma cacao (only in Vandeikya), Chasmanthera dependens (Vandeikya), Swartzia madagascaris (Vandeikya). This agrees with the report that unique plants in home gardens varies with ethnicity, culture, religion and spirituality. Tree species such as Ceiba petandra (5.72%), Carica papaya (5.31%), Newbouldia laevis (5.03%), Mangifera indica (4.97%), Moringa oleifera (4.90%), Jatropha curcas (4.55%) and Gmelina arborea (4.41%) were the most frequently occurring and most abundant tree species found in home gardens in Benue State. Home gardens in Benue State have diverse plant species. However plant species such as Caesalpinia bondue, Borassus aethiopum, Theobroma cacao and Phoenix dactylifera were not abundant with a percentage of 0.07% each. Some plant species found in Tiv speaking areas were not found in either Idoma or Igede areas that were visited during the study. Plant species such as Emilia coccinea, Caesalpinia bondue, Borassus aethiopum, Theobroma cacao, Phoenix dactylifera, Swartzia madagascriensis, Commiphora kerstingii, Lophira lanceolata, Eurphorbia hirta and Chasmanthera dependens were not found in both Idoma and Igede areas that were covered in the study (Table 2). Plants species like Chrysophyllum albidum (0.14%) was found only in Idoma area but it was not found in Tiv and Igede areas. Pterocarpus santaliniodes (0.48%) was found only in Igede but it was not found in Tiv and Idoma areas.

Medicinal plants found in home gardens in Benue state

Various Home garden plant species were identified for medicinal purposes (Table 6). A lot of medicinal plants were found in home gardens in Benue State. Several types of ailments were found to be treated with the home garden medicinal plants. The ailments treated ranges from common ailments like cough, stomach pain to severe ailments like stroke, hepatitis B. Twenty two (22) plant species were found to be the most frequently used medicinal plants in home gardens in Benue State (Table 7). Out of the 22 plants, Ceiba petandra had the highest percentage (23.33%) followed by Moringa oleifera (15.83%) and Cymbopogon citratus (10.00%). These top three plants were selected for phytochemical screening based on their percentage of use. Ceiba petandra is used to treat different ailments like hypertension, mystic diarrhea, partial madness and fracture. Its leaves are used as vegetables. Moringa oleifera is used to treat ulcer, diabetes, typhoid, body weakness and fever. Cymbopogon citratus is used to treat cough, dizziness, hook worms, gonorrhea and stomach upset. Eurphorbia hirta and Citrus aurantifolia had the smallest percentage (0.42%) each.

CONCLUSION

Home gardens in Benue State have diverse species of plants which have numerous uses ranging from their use as food, shade and medicine. Some of these plant species are naturally established in the home gardens and are being maintained, conserved or protected by home garden owners because of the diverse uses the plants offer. While others are deliberately planted by home garden owners because of how scarce the particular plant species is, especially those of medicinal importance. The most frequently used medicinal plant species include in Home gardens in Benue State include; Ceiba petandra, Moringa oleifera and Cymbopogon citratus. Most of the home garden owners in Benue State are elderly people who have remained faithful to the conservation and maintenance of useful plants they have inherited from forefathers.

1.  Gautam R, Suwal R, Shrestha PK (2004) Status of home gardens of Nepal: Findings of baseline survey conducted in four sites of home garden project. Paper presented at the Second National Sharing and Learning Workshop of Home gardens in Pokhara, LI-BIRD, Nepal.

2.   Abdollah OS, Pariskesit GB, Hadikusumal HY (2002) Home-gardens in the upper citarum watershed, West Java: A challenge for in situ conservation of plant genetic resources. International Genetic Resources Institute, Rome.

3.   Sunwar ST, Thomstron CG, Subdeb A, Bystron M (2006) Home gardens in Western Nepal: Opportunities and challenges for a West Nepal: Opportunities and challenges for on-farm management of agro-forestry biodiversity. Biodivers Conserv 15: 4211-4238.

4.   Kumar BM, Nair PKR (2006) Tropical home gardens. A time tested example of sustainable Agroforestry. Springer.

5.   Lerato YM (2011) An assessment of the useful plant diversity in home-gardens and communal land of Tihakgameng, North West University. Available online: http://www.citeseerx.ist.psu

6.  Buchman C (2009) Cuban home-gardens and their role in social ecological resilience. Hum Ecol 37: 705-721.

7.  Garau J (2006) Impact of antibiotic restrictions: The ethical perspective. J Microbiol Infect 4: 16-24.

8.   World Health Organization (2008) Traditional medicine. Facts Sheet No.134, Vienna.

9.    Siebert U (2007) Languages of Benue state. Nigerian Languages. Department of Languages and Linguistics, University of Jos, Retrieved on 22^nd June, 2017.

10. Melese M, Fitamo D (2015) Plant species diversity and composition of the home gardens in Dilla Zuriya Woreda, Gedeo Zone, SNNPRS, Ethiopia. Plant 3: 80-86.

11. Agbogidi OM, Adolor EB (2013) Home gardens in the maintenance of biological diversity. Appl Sci Rep 1: 19-25.

12. Regassa R (2016) Useful plant species diversity in home gardens and its contribution to household food security in Hawassa. Afr J Plant Sci 10: 211-233.

13. Amanda OS, Columba MO, Romero AM, Luna-Cavazos M, Castillo PE (2015) Multi-purpose functions of home gardens for family subsistence. Bot Sci 93: 791-806.

14. Eyzaguirre P (2006) Agricultural biodiversity and how human culture is shaping it. In: Cernea M and Kassam A (eds). Researching the culture in agriculture CABI, Wallingford, UK, pp: 264-284.