Use plant extracts as biopesticide and plant leaves as biofertiliser for soil amendments, to improve production, nutritional content and organoleptic properties of soybean grown in Cameroon

I began research in 2001 in the field of plant disease control as a master level student with a dissertation entitled: « Stabilite et activite antifongique de cinq huiles essentielles contre Bipolaris oryzae (shoem.) ». I continued in 2005 with another DEA thesis with the theme: « Potentiel preservatif alimentaire naturel de trois huiles essentielles contre deux souches mycotoxiques de Penicillium expansum ». In Ph.D, research has shown that the approach combining the treatment of rice seeds with the essential oil of Callistemon citrinus, the spraying of rice plants with the ethanolic extract of the same plant followed by its aqueous extract was effective in increasing the yield of rice production by up to 140% compared to the untreated control. In addition, in collaboration with other researchers, it has been shown that when maize grows Tithonia diversifolia powder as a biofertilizer, production yields range from 1.8 t/ha to 6.4 t/ha or nearly 250% increasing compared to the control and 100% compared to synthetic fertilizers.

The soybean production in Cameroon increased from 14,300 tons in 2013 to 27,000 tons in 2017. Despite the two fold increase, the national soybean production still too low compared to the world production that stood at 277, 000, 000 tons – 352, 000, 000 tons. Cameroon imports 50% of soybean used for livestock feed.  As consequences of low crops’s production, poverty is growing and migration of youth out of rural ereas to urban centres is escalating. Plant quarantine stations in Cameroon are not efficient mainly due to a lack of experienced analysts and inadequate testing facilities. Uncontrolled importation of virtually all the stock of cereals, soybean and exotic vegetable seeds is one of the problem facing seed production and multiplication in Cameroon.

Conventional farming also described as industrial farming, is a system of production that utilizes synthetic chemical inputs such as fertilisers and pesticides. Methods of production include raising livestock in Concentrated Animal Feeding Operations (CAFOs), heavy irrigation, tillage and concentrated monoculture production for crops. While this system, is highly productive, it is incredibly energy and resource intensive and contributes to negative effects on the environment, human health, and social equity. Galani et al. 2018 reported that the residues of 62 pesticides found in crop grown in Cameroun, with 17.2% in soybeans.

Thus, the Food and Agriculture Association of the United Nations (FAO) have identified a need for change due to the depletion of natural resources and need to feed the global growing population. One option is to increase attention towards a more ecological approach, in which food is produced in a sustainable manner that minimizes global environmental impacts while still providing fresh, nutritious food to consumers: organic agriculture. Organic farms tend to have greater flora and fauna, encouraged by the prohibition of agrochemicals that can upset the balance of the natural ecosystem. In organic systems, biodiversity of crops and livestock helps to create resilience to disease and pests. The UN projects that the global population will increase from 7 billion to more than 9 million by 2050, of which the majority is expected to occur in Africa. To anticipate such population growth, agricultural systems need to become more sustainable and better linked to nutrition performance by strengthening the agro biodiversity of resilient cropping systems, thereby increasing the range of food products for a balanced, healthy diet. Maize, rice and soybean are among the African food varieties which are main sources of starch, plant proteins and oils.

Soybean (Glycine max L.) is an annual legume grown for its edible bean. Soybean is a source of both protein and energy: it has about 40 per cent protein and 20 per cent vegetable oil by weight in its seeds. It produces more protein per hectare than any other major crop, and has a higher percentage of protein than many animal products. Around three-quarters of soybeans worldwide are used for animal feed. Consuming 15-25g soybeans protein per day can lower LDL cholesterol by as much as 10%, several studies show that consuming around 50-80mg soybeans isoflavones daily for 8-12 weeks can help lower hot flush frequency and severity by 25% in menopausal symptoms. In the Cameroon traditional system of medicine, herbal preparations and mixtures as well as edible plants or seeds are used to treat or prevent diseases. There is lack of efficacy and safety evidence on these medicinal plants, meanwhile edible products suppose their safeness, this render urgent the necessity of bringing scientific proof to the claimed properties. Among these plants, soy and soy derivatives are largely consumed for their supposed health benefits regarding the management of some menopausal symptoms, including amenorrhea, vaginal dryness, hot flushes, immune system reinforcing. Thus the aim of our study would be to evaluate the benefits/risk ratio of the usage of soybean beverage and polyphenols for complementary treatment of menopause symptoms and some hormone related gynaecologic cancers. Cameroon production (tons) 29,558 and importation 15,000 tons (20 million USD) in 2016 according to the ministry of economy.

In Cameroon, many local plants are reported to possess inhibitory properties in vitro against various pathogens. However, most of the work on plant extracts as an alternative to synthetic fungicides are limited to in vitro assays and controlled environments. Little is known on the effectiveness of plant extracts on the on-farm control of biotic agents and treatment effects on grains’ nutrients content soybean in Cameroon.

The project aims in developing sustainable and environmental friendly products to control plant diseases and for soil fertilisation.

The overall objective of the project is: To assess the beneficial effects of treatments with extracts of Callistemon citrinus as biopesticide and soil amendment with powder of Tithonia diversifolia as biofertiliser as compared to synthetic chemical inputs on the production of soybean grown in Cameroon for food, nutrition, security and sustainable agriculture.

The thesis statement of the project is: Increase number of farmers growing soybean in Cameroon due to more quality and quantity soybean produced from green inputs will reduce soybean importation, improve livestock health and human diet. Increased agricultural growth is a major agenda in almost all African sub-Sahara countries. Efforts are being made to ensure food security for all through improved availability of inputs (seed, fertiliser, pesticides, irrigation facilities etc.).

Joseph Blaise Dongmo Lekagne, Cameroon


  1. ” Le projet vise à développer des produits durables et respectueux de l’environnement pour lutter contre les maladies des plantes et pour la fertilisation des sols”
    Très interessant , félicitations et bon courage.


  2. Très bon projet avec ça je pense que le Cameroun et l’Afrique pourra atteindre l’auto suffisance alimentaire beaucoup de courage


  3. Projet très intéressant! Ça permettra d’augmenter le rendement de la production agricole. Vivement qu’il se réalise.


  4. Projet très intéressant. Utiliser les extraits de plantes pour lutter contre les maladies des plantes c’est formidable car selon moi ça réduirai aussi le taux d’intoxication alimentaire qui crée des maladies via les aliments que nous consommons. Bon courage pour la suite


    1. Il sagit là d’un projet très intéressent dans ce sens que les pesticides et les engrais chimiques sont de plus en plus considérés comme un fléau pour la santé humaine et l’environnement car leurs finalités est d’êtres toxiques et mortels pour nombre d’être vivants. Compte tenu de l’innocuité avérée des plantes, l’utilisation de leurs extraits comme biopesticides et comme biofertilisants représente un des moyens les plus sûrs de préserver l’Homme de plusieurs maladies telles que le cancer, le diabète, l’hypertension, certaines dermatoses entre autres. Vraiment félicitations et surtout bon courage…


  5. Soy beans are one of the major crops our country Cameroon needs for its food security. The project Dr Dongmo has developed intends not only to optimize the production of soy beans, but also to promote ecology friendly agriculture. The achievement of the objectives of this study will provide our country with affordable and ecological biopesticide and contribute to reduction of the country dependence to food imimportations. The implementations of results of this project could boost agriculture in our rural areas, create employment and slow down youth migration out villages. I therefore favorably and strongly encourage and support such initiative.


  6. Bio fertilizers are better than chemical ones in order to protect not just the environment but human health as well; with all these Cancer issues going on these days. This is a research to encourage. Good job!!!


  7. Very good research work. This is another scientific proof that bio fertilizers are better than synthetic ones. Very good initiative.


  8. Le projet est très intéressant. Il permettra de réduire les résidus pesticides dans les aliments que nous consommons, mais aussi réduira la pollution de l’environnement en effectuant cette culture biologique à partir des intrants d’origine de plante.


Comments are closed.

%d bloggers like this: