Pepper fruit (Dennettia tripetala) is an old variety with great medical benefits.
Photo: © World Agroforestry

African old variety permanent crops could face extinction

Permanent crops are plants that can survive for years in a certain favourable environment and do not require as much care as temporary crops to bear fruits. These crops do not end their lives with the harvesting season, rather they stay in the environment to promote, protect and maintain biodiversity. Alongside familiar permanent crops such as cocoa, etc., there are old varieties. Many of the old varieties of permanent crops in Nigeria and other African countries are threatened with extinction.

Nigeria has an arable land area of 34 million hectares: 30.3 million hectares on meadows and pastures, but just 6.5 million hectares for permanent crops. Agriculture accounts for over 20 per cent of Nigeria's GDP. The country is a leader in various types of agricultural production, such as palm oil, cocoa beans and pineapple.

However, Nigeria is also home to rare and little known permanent crops such as Ube okpoko or African olive (Canarium schweinfurthii), Ukpa or African walnut (Tetracarpidium conophorum), Mmimmi or pepper fruit (Dennettia tripetala) or others only bearing local names, such as Udala Nwa enwe. These old varieties of permanent crops are not popular, and there are many of them, varying from region to region, and the local community gives them names based on their taste, shapes, animals that feed on them, etc.

Cultivation bears problems

Many of these varieties are threatened with extinction, for which there are many reasons. In addition to many plants being only little known and not widespread, it can take up to ten years after initial planting for them to be harvested for the first time.  People find it discouraging to plant them as plantation farming. And most villagers hardly know how to process the seeds of such crops before planting in the nursery. In addition, each variety requires different harvesting methods, which vary from the size of one plant to the other. For example, African olive, which can attain a height of about 40 feet and above, makes a harvest of matured fruits a difficult task. Besides this, permanent crops require large areas of land for them to be established.

However, in addition to the agricultural factors, trade-conditioned obstacles present problems. Most of the rare old varieties are not produced, harvested and packaged according to international standards, which is why there is no trade certification and hence hardly any market outside the region they are grown in, let alone an international market. And this state of affairs is not going to change in the near future, for there is hardly any government attention which could enable such produce to receive trade certifications and thus be traded internationally. But without international markets as a target, going into plantation farming of these rare permanent crops can’t be successful. The reason why the government is not making any efforts here is that the permanent crops are not regarded as a potential source of income. So they get hardly any support regarding research and development.

There are many economic and ecological benefits

However, these old varieties do indeed bear a wide range of benefits. From an economic angle, they can provide a good source of income to the people in the community where such rare plants grow. Some people who have access to the urban areas do take the fruits to the urban markets to sell them and make a living out the proceeds.

In addition, the old varieties can preserve the ecosystems and reduce climate change factors. For most of these permanent crops are deciduous in nature and can help in gaseous exchange by reducing the amount of carbon dioxide in the atmosphere.  They serve as cover crops to prevent leaching, erosion, flooding, wildfire, etc. Such plants also provide housing and feeding to many animals, like birds, bees, etc. So they ensure good biodiversity in the communities where they are found. All these plants are good sources of forest and animals’ conservation and support balance in ecosystem.

Plants with a medical benefit

Furthermore, many of the plants are of medical or nutrition-physiological use which requires more research. For example, the African walnut (Tetracarpidium conophorum) contains a lot of minerals and vitamins. This plant can be used to treat gastroenteritis diseases or to lower cholesterol levels. A recent study indicates that walnut extract could even be helpful in treating Parkinson and Alzheimer.

Another plant, pepper fruit (Dennettia tripetala), has been used for centuries in the Ayurveda system of medicines to treat various illnesses. The phyto-chemical composition of pepper fruit includes, for example, alkaloids, tanning agents, saponins, flavonoids, terpenoids, steroids and heart glycosides. Anti-oxidative, anti-diabetic, antibacterial, blood pressure-lowering, spasmolytic, anti-inflammatory and further properties have been demonstrated. Thus pepper fruit is very valuable for pharmacological purposes.

These are just two of the plants belonging to the old and rare varieties for which research results are already available. But there are also numerous unidentified permanent crops which would first have to be classified and then researched. They could contribute to topics such as food security, bioeconomy, biodiversity, and climate change actions. Some of the plants which are particularly valuable from a medical or nutrition-physiological angle would also bear the potential to be an economic success. However, this would require investing enough time, energy, finance, research, and marketing in these plants. 


Muoedu Uzondu Emmanuel is a soil scientist/agriculturist based in Anambra State, Nigeria. Contact:



Dauda Muhammed, Yetunde H. Adebiyi, Bernard O. Odey, Rahmatallah A. Alawode, Abdullateef Lawal, Banke Mary Okunlola, Jonathan Ibrahim and Eustace Bonghan Berinyuy : Dennettia tripetala (Pepper Fruit), a review of its ethno-medicinal use, phytoconstituents, and biological propertiesk, GSC Advanced Research and Reviews, March 2021,DOI:

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Ngozika Okoye: Ube Okpoko, the African Olive, Pharmanewsonline, June 2022

Sylvia Oghogho Iseghohi: A Review of the Uses and Medicinal Properties of Dennettia tripetala (Pepperfruit), Med. Sci. 2015, 3(4), 104-111, DOI: 10.3390/medsci3040104

Trading Economics Nigeria: Permanent Cropland (% Of Land Area)

Statista: Agriculture in Nigeria - statistics and facts

Peter Olowa: Nigeria’s Agricultural land use to grow by 5% in 2021, MSMEs TODAY, December  2020


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