Biology, Medicine, & Natural Product Chemistry  ISSN 2089-6514 (paper) 
Volume 12, Number 1, April 2023 | Pages: 335-341 | DOI: 10.14421/biomedich.2023.121.335-341 ISSN 2540-9328 (online) 
 

 

 

El Hadji Gorgui Diouf1,*, Doudou Diop2, Abdoulaye Gueye1, Mbaye Diouf1, Talibouya Ndior1, 

Mamadou Latyr Ndour1, Adama Faye1, Mamadou Kébé1 
1Laboratory of Natural Products, Department of Chemistry, Faculty of Science and Technology; Cheikh Anta Diop University of Dakar, Senegal. 

2Botany Laboratory, Fundamental Institute of Black Africa, Cheikh Anta Diop University of Dakar, Senegal. 

 

 

Corresponding author* 
goorgui82@yahoo.fr 

 

 
Manuscript received: 22 March, 2023. Revision accepted: 28 March, 2023. Published: 02 April, 2023. 

 
 

Abstract 

 

Crop losses in vegetable crops due to nematodes are a concern in a country like Senegal where food demand is increasingly high. The use 
of chemical pesticides has made great progress in increasing harvests in Senegal. But these pesticides have negative eff ects on the 

environment and on human health. Crops are often contaminated as well as groundwater. The use of natural products to remedy t his 

phenomenon is very important, especially in areas such as the Niayes zone where the climate and soil are very favorable for market 

gardening and where water contamination is very sensitive. The aim of our study is to identify the plants used to control nematodes in the 
Niayes area of Thiès. To this end, we conducted an ethnobotanical survey of 100 people of different ages and sexes in this area. The 

results showed 17 plant species used to control nematodes in 12 families. Among these species, the most cited were Azadirachta indica A. 

Juss. Juss, Calotropis procera (Ait.) F. and Cassia Occidentalis L. Leaves (71%) are mostly used. The sample is often dried and ground 

(45%) or fresh (case of hydrodistillation) (53%) before preparation. Water (92%) is the most used solvent for extraction. Mac eration 
(85%) and infusion are the most common preparation methods. The application of these preparations by systemic action (94%) is more 

adopted than fumigation. Local people find these preparations rather effective (78%), which is very encouraging. The present study 

constitutes a database for further studies in the field of Senegalese pharmacopeia. In addition, scientific research on bionematicidal 
substances may be conducted in the future to evaluate the effectiveness of these plants identified in the Niayes area of Thiè s for the 

protection of vegetable crops against nematodes. 

 

Keywords: Ethnobotanical survey; Senegalese Pharmacopoeia; Nematicidal plants; Market gardening; Niayes area; Niayes area of Thiès. 

 

Abbreviations: UCAD: Université Cheikh Anta Diop de Dakar; IFAN: Institut Fondamental d'Afrique Noire. 

 
 

INTRODUCTION 
 

Agriculture is a major industry that contributes to 
socioeconomic development and employs nearly 40% of 

the world's working population (MOMAGRI, 2016). In 
West Africa, agriculture contributes about 35% of the 

countries’ gross domestic product (GDP). It remains the 
main provider of employment (60% of the active 
population) but also contributes to more than 80% of the 

population's food needs (Blein R. et al, 2008). The 
economic development of these countries can only be 
based on agriculture. In Senegal, agriculture in the 

Niayes area plays an important role in supplying the 
population with agricultural products. It provides more 

than 80% of the national vegetable production (DPS, 
2003). Very fertile and favorable for market gardening, 
the Niayes zone is characterized by a shallow 

groundwater table (0.5 to 5 meters deep) and is made up 
of dunes and depressions (ANSD, 2015). The Niayes 
soils are of the tropical ferruginous type, weakly leached 

on sand (dior), with a sandy texture and 90 to 95% total 
sand. They have very low levels of carbon (0.2% on 
average), total nitrogen (0.15 to 1%), and exchangeable 

bases (1.77 meq/100 g). The pH is slightly acidic at 5.5 
to 6.5 (Adejumo, 2013). Despite all the advantages of this 

soil, yields are below expectations because the crops are 
often attacked by predators that cause huge crop losses. 
Nematodes are the main pests of vegetable crops. They 

attack crops such as aubergines, tomatoes, cabbage, 
potatoes, etc. Thus, the population often resorts to 
chemical pesticides (or synthetic pesticides) which are 

certainly effective against these parasites, but at the same 
time disrupt biodiversity by eliminating insects that are 

not necessarily harmful and pollute the soil and 
contaminate the crops. According to the FAO, nearly 
750,000 people contract chronic illnesses, including 

cancers, each year as a result of exposure to pesticides. In 
addition, several pathologies are directly associated with 
them in the long term, such as congenital malformations, 

 

Ethnobotanical Survey on the Plants Used in the Control of 

Nematodes in the Zone of es Niayes de Thies/Senegal 
 

https://doi.org/10.14421/biomedich.2023.121.335-341


 

 

 

336 Biology, Medicine, & Natural Product Chemistry 12 (1), 2023: 335-341 
 

 

mental deficiencies, neurological and reproductive 

disorders, endocrine disruptions, weakening of the 
immune system, and some cases of cancer (Dewailly E, 
2000; Petrelli G, 2001; Eriksson M, 2008). Yet in 

Senegal, chemical nematicides, although classified as 
extremely toxic, are sold by dealers (Diarra A, 2017) in 

an uncontrolled manner and with ignorance of the 
consequences. It is therefore urgent to find solutions 
against this phenomenon of the spread of chemical 

pesticides. The idea is to find pesticides that are not toxic 
to humans and do not pollute the environment. So what 
better way than to use biopesticides. 

Since the discovery of active ingredients of 
therapeutic interest from plant species selected according 

to criteria based on medical ethnobotany and 
ethnopharmacology is more frequent than in a simple 
random screening of plants (Svetaz L et al, 2010) and 

given that there are no or almost no nematological 
studies in the Niayes area of Thiès, we conducted an 
ethnobotanical survey among local farmers in this area in 

order to identify the plants used in the fight against 
nematodes as well as the methods of preparation of 

extracts from these plants. The present work is also part of 
the global framework of the valorization of the 
Senegalese flora. 
 

 

MATERIALS AND METHODS 
 

Selection of the ethnobotanical survey site 
The Niayes zone extends from Dakar to Saint Louis, in a 
strip 180 km long and 5 to 30 km wide (Fall AS, 2001). 

It constitutes a rather original environment characterized 

by dunes and depressions that are kept wet or flooded for 
a good part of the year and by a sub-surface water table 
(see Figure 1) (Cissé I, 2008). Its soils are very favorable 

for market gardening. Administratively, it covers part of 
the regions of Saint-Louis, Louga, Dakar, and part of the 

region of Thiès, namely the departments of Tivaouane 
and Thiès. Our study area concerns these two 
departments, more precisely the rural 

communes/communities of Kayar (located in the north-
west of the department of Thiès), Notto Gouye Diama, 
and Darou Khoudoss (located in the west of the 

department of Tivaouane) (see Figure 2). Very few 
studies have been carried out on potential nematicidal 

plants used for the protection of vegetable crops in this 
area. 
 

 

 
 
Figure 1. Level of fluctuation of the water table according to the seasons 

(Cissé I, 2008). 

 

 
 

 

 
 

Figure 2: Location of the study area. (Source: inspired by (https://www.au-senegal.com/), Realisation: authors) 

 
 

Method of data collection 
The area was divided into different sites and visits were 
made to each site in July and October 2021. The 

ethnobotanical study was carried out through a series of 

surveys using a pre-designed questionnaire divided into 
two parts. The first question concerned the socio-
demographic situation of the respondent and the second 

question concerned the names of the species used for 

http://www.au-senegal.com/)


 

 

 

 Diouf et al. – Ethnobotanical Survey on the Plants Used in the Control of … 337 
 

 

nematode control, the parts of the plant used, the times of 

harvest, the methods of preparation of the extracts, etc. 
The identification of the scientific names of the plants 

was carried out in the botanical laboratory of 
IFAN/UCAD. The scientific name of each species was 
transcribed into the local language using the lexicon of 

vernacular names of J. G. Adam (Adam J.G, 1970). 
 

Data processing 

The data recorded on the survey forms were processed 
and entered into Excel. The data were analyzed using 

simple descriptive statistical methods. Quantitative 
variables are described using the mean and qualitative 
variables are described using percentages. 

 

 

RESULTS 
 

In this study, all the respondents were farmers. The 
population is made up of 100 informants, 43 of whom are 

from Notto Gouye Diama, 10 from Darou Khoudoss, and 
47 from Kayar, i.e. 53 in the department of Tivaouane 
and 47 in the department of Thiès. 

 

Description of the study population by age 
Figure 1 shows the age distribution of the sample 

studied. We note that the age extremes of the informants 
vary between 18 and 78 years with an average age of 48 
years. The majority (71%) were in the 30-60 age group, 

while the under-30 age group had the lowest rate of 
nematicide users (6%). 

 

Distribution by gender 
Figure 2 shows the gender distribution of the study 

sample. In this study, the majority of informants were 
male (90%) and 10% were female, with a sex ratio 
(male/female) of 9. 

 

Description of the study population by family status 

Regarding the family situation, 94% of the informants 
have children, 3% say they have no children and 3% gave 
no answer (see Figure 3). 

 

 
 

Figure 1. Distribution of respondents by age group. 

 

 
Figure 2. Distribution of respondents by gender. 

 

 
Figure 3. Distribution of the study population by family status. 

 

Distribution of plants by frequency of citation 
The surveys carried out in the Niayes area of Thiès 
enabled us to identify different plant species used in the 

control of nematodes. The list of the different plant 
species selected and their frequency of use are presented 
in Table 1. The ethnobotanical survey identified 

seventeen (17) plant species of which Azadirachta indica 
A. Juss. Juss. represents the most used plant with a 

percentage of 45%, followed by Calotropis procera 
(Ait.) F. (20%) and Cassia Occidentalis L. with a 
percentage of 9%. 

 

 

 
 

Table 1. List of plants used for nematode control in the study area, ranked by frequency of citation. 

 

Family Scientific name of the plant Local name Frequency of citation 

Meliaceae Azadirachta indica A. Juss. Nim 45% 

Asclepiadaceae Calotropis procera (Ait.) F. Paftan 20% 

Cesalpiniaceae Cassia Occidentalis L. Bèntamaré 9% 

Fabaceae (= Papilionaceae) Arachis hypogaea L. Gèrté, tiga. 7% 

Fabaceae (= Papilionaceae) Capsicum frutescens L. Kani 3% 

Caricaceae Carica papaya L. Papaya 2% 

Liliaceae Allium sativum L. Garlic 2% 

Meliaceae Khaya senegalensis (Desv.) A. Juss Khaye 2% 

Labiatae Ocimum basilicum basil Ngungun 2% 

 



 

 

 

338 Biology, Medicine, & Natural Product Chemistry 12 (1), 2023: 335-341 
 

 

Table 1. Cont. 

 

Family Scientific name of the plant Local name Frequency of citation 

Combrétacées Guiera senegalensis J. F. Gmel Ngèr (in Wolof) 1% 

Solanaceae Datura metel L. Katidiâdabé 1% 

Fabaceae (= Papilionaceae) Indigofera suffruticosa Mill. Ngâdj, ngâdièn 1% 

Euphorbiaceae Ricinus communis L. Khekhem 1% 

Moringaceae Moringa oleifera Lam. Nevèrday, sap sap 1% 

Euphorbiaceae Euphorbia balsamifera Ait. Salan 1% 

Euphorbiaceae Jatropha curcas L. Tabanani 1% 

Poaceae (= Grasses) Zea mays L. Mbokha 1% 

 
 

The species listed are divided into twelve (12) 

families. The most commonly used plants are from the 
Meliaceae (47%) and Asclepiadaceae (20%) families. 

The species used in the medium range belong to the 

Fabaceae (11%) and Cesalpiniaceae (9%) families (see 
Table 2). 

 

 

 
Table 2. List of plant families used for nematode control in the study area, arranged in alphabetical order. 

 

Family Scientific name of the plant Frequency of citation by family 

Asclepiadaceae Calotropis procera (Ait.) F. 20% 

Caricaceae Carica papaya L. 2% 

Cesalpiniaceae Cassia Occidentalis L. 9% 

Combrétacées Guiera senegalensis J. F. Gmel 1% 

 

Euphorbiaceae 

Ricinus communis L. 

Euphorbia 

balsamifera Ait. 

Jatropha curcas L. 

 

3% 

 

Fabaceae (= Papilionaceae) 

Arachis hypogaea L. 

Capsicum frutescens 
L. Indigofera 

suffruticosa Mill. 

 

11% 

Labiatae Ocimum basilicum basil 2% 

Liliaceae Allium sativum L. 2% 

Meliaceae Azadirachta indica A. Juss. 

Khaya senegalensis (Desv.) A. Juss 

 

47% 

Moringaceae Moringa oleifera Lam. 1% 

Poaceae (= Grasses) Zea mays L. 1% 

Solanaceae Datura metel L. 1% 

 
 
 

The most commonly used plant parts 
The distribution of the study sample according to their 
use of plant parts for nematode control is shown in 

Figure 4. The most used parts are leaves (71%) and seeds 
(27%). 

 

Harvest times 
The plants are harvested during the day, throughout the 

year, and especially in August. 
 

The physical state of the plant before the preparation 

of the extracts 
Plant samples are often freshly harvested and then 
extracted (53%) or first ground and then dried before 

extracts are prepared (45%). Very rarely is plant material 
dried without being ground (2%) (Figure 5). 

The solvent used for preparation 
Water is the most used solvent (92%) while oils are very 
little used (8%). Figure 4 shows the distribution of 

solvents used for the preparation of extracts (Figure 6). 
 

Method of preparation of extracts 
Maceration is widely used (85%), followed by infusion 
(7%). Hydrodistillation (4%) and the direct use of plant 

juice (4%) are not widely practiced (Figure 7). 
 

How to apply the extracts 

Figure 9 shows the distribution of application modes of 
plant extracts. The rate of application by systemic action 
was 94%, while only 6% of the study sample used 

fumigation (Figure 8). 



 

 

 

 Diouf et al. – Ethnobotanical Survey on the Plants Used in the Control of … 339 
 

 

Evaluation of the effectiveness of the plants by the 

study population 
In the course of our survey, we asked the respondents to 

give their assessments of the effectiveness of the plant 
preparations they had to apply to their plantations. Thus, 
78% of people said that they were moderately effective, 

20% said they were very effective and only 2% said they 
were not very effective (Figure 9). 
 

 

 

 
Figure 4. Distribution of plant organs by use. 

 

 

 

 
Figure 5. Physical state of the plant before preparation of the extracts. 

 

 

 

 
Figure 6. Solvents used. 

 

 

 

 
Figure 7. Methods of preparing extracts. 

 
Figure 8. The modes of application of extracts. 

 

 

 
Figure 9. Effectiveness of plants according to respondents. 

 

 

DISCUSSION 
 

The African population is attached to traditional 
phytopharmacy. In Senegalese households, men 
traditionally have the role of doing large-scale fieldwork 

and any other activity that requires muscular effort. 
Women are only involved in small-scale cultivation. 

Several ethnobotanical surveys conducted in Senegal 
have shown that in the field of traditional phototherapy 
and everything related to agriculture, men are much more 

represented than women. Thus, men are more likely to 
have knowledge of nematicidal plants than women. In 
this sense, our results are similar to those of Barry (male: 

91%, female: 9%) (Barry, 20015) and DIOP (Diop, 
2015) in which men are forty (43) times more 
represented than women. Individuals in the 30 to 60 age 

group are more likely to acquire more knowledge, 
especially about nematicidal plants, in order to ensure 

good yields to better feed their families, unlike the very 
young who do not have many responsibilities (no 
children to feed). The over-60s are well represented 

because traditional knowledge is kept by the elderly, who 
then pass it on to responsible young adults. 

The massive use of the species Azadirachta indica A. 

Juss. and the species Calotropis procera (Ait.) F. is 
probably due to their insecticidal powers already observed. 

The bitter taste, and the insecticidal properties towards 
mosquitoes (Pousset J.L, 1989) of Azadirachta indica A. 
Juss. have probably led local people to believe that it is 

also a plant that can be used against nematodes. The 
great abundance of this plant in Senegal makes it easy to 
obtain and it is by far the most used plant. Azadirachta 

indica A. does have nematicidal effects (Yarou B.B). 
Calotropis procera (Ait.) F. is also widespread in 

Senegal. It grows well in the streets of Senegalese 



 

 

 

340 Biology, Medicine, & Natural Product Chemistry 12 (1), 2023: 335-341 
 

 

villages. The plant has been reported to have nematicidal 

properties (Rao et al., 1996; Ahmed et al., 1996). These 
plants (Azadirachta indica A. Juss. and Calotropis 
procera (Ait.) F.) are available throughout the year. 

However, for the rare plants, it is in August that the 
harvesting is done because it corresponds to the wintering 

period. We note a great diversity of plant families used in 
the fight against nematodes. We note that the Meliaceae, 
Asclepiadaceae, Fabaceae, and Caesalpiniaceae are the 

most cited plant families, but in terms of the number of 
species represented, we have 3 species among the 
Euphorbiaceae and 3 species among the Fabaceae, and 2 

species for the Meliaceae. The latter may have a 
common trait of being rich in nematicidal compounds 

which are found in these species. 
The majority use of plant leaves can be explained by 

the fact that leaves are rich in active ingredients and are 

considered the most accessible part of the plant. Leaves 
are the storage place for secondary metabolites that are 
responsible for the biological properties of the plant. A 

study by Diatta et al (Diatta C.D, 2013) (46% for leaves) 
showed that leaves were the most used as drugs in the 

preparation of traditional medicinal recipes. 
Water is a widely used solvent (92%) compared to 

oils. This says that most extracted compounds are polar. 

These are probably polyphenols, among which there are 
nematicidal molecules. As for preparation methods, 
maceration and infusion are the most commonly used 

methods. Maceration is the easiest extraction to 
implement and does not require any volume of solvent to 
be boiled beforehand, unlike other extractions. Infusion 

with a polar solvent allows good extraction of water-
soluble active ingredients and even those that are weakly 

soluble in their pure state (Benlamdini A, 2014). The 
fumigation method of the application represents only 6%. 
It is a difficult method to implement compared to 

systemic action (94%). Fumigation is only more effective 
if it is carried out in an enclosed area so that the gas has a 
much greater effect on the pests. But the means of the 

local population in Thiès, as for most local African 
populations, are generally modest to manage hectares of 

field land with fumigation. Many informants found the 
plants they tested to be moderately or very effective. It 
may be that these plants contain very good amounts of 

nematicidal secondary metabolites. This is very 
encouraging and needs to be verified by biochemical 
studies. 

 
 

CONCLUSION 
 

Ten (17) species of nematicidal plants were selected for 

this study. The study revealed that men are more 
knowledgeable about nematicidal plants than women. 
Individuals in the age group 30-60 years, who most often 

have children, are more numerous than other individuals. 
Our survey shows that the foliage is the most used part. 

The plants mentioned are available in the study area and 

people mostly use the species Azadirachta indica A. Juss. 
and Calotropis indica A. Juss. Juss. and Calotropis 
procera (Ait.) F. for nematode control. They can harvest 

these plants throughout the year. Before preparation, the 
plant sample is often dried and crushed or is fresh (case 

for hydrodistillation). Maceration and infusion are the 
most common methods of preparing extracts. The 
application of these preparations by systemic action is 

more widely used than fumigation. Local people find 
these preparations rather effective, which is really 
encouraging. Furthermore, these results can be seen as a 

source of information for scientific research on 
biopesticides that may one day permanently replace 

dangerous chemical pesticides. The plants mentioned in 
this survey may offer broad answers to nematode-related 
problems. 

 
Acknowledgments: Acknowledgments are expressed in a 

brief; all sources of institutional, private, and corporate 
financial support for the work must be fully 

acknowledged, and any potential conflicts of interest are 
noted. 
 

Authors’ Contributions: El Hadji Gorgui DIOUF 
designed the study. Mbaye Diouf carried out the 
fieldwork. Doudou Diop carried out the botanical 

identification of the species surveyed. El Hadji Gorgui 
DIOUF and Abdoulaye Gueye analyzed the data and 
wrote the article. All authors read and approved the final 

version of the manuscript. 
 

Competing Interests: The authors declare that there are 
no competing interests. 
 

 

REFERENCES 
 
Adam J.G. Noms vernaculaires de Plantes du Sénégal (fin). In: 

Journal d'agriculture tropicale et de botanique appliquée, vol. 
17, No. 10-11, October-November 1970. pp. 402-460. 

Adejumo, B. A., Okundare, R. O., Afolayan, O. I. and Balogun S. 

A., Quality abattributes of ignam flour (Elubo) as affected by 

blanching water temperature and soakinf time. Intl. J. Engr. Sci 

(IJES), 2013, 2 (1): 213-221. 

Ahmed et al, Effect of soil amendment with Calotropis procera for 

the control of Meloidogyne javanica infection on egg plant. 

Pakistan Journal of Nematology. 1996, 14 (1): 55-59. 

ANSD, Situation Economique et Sociale régionale-2013, 2015. 

Barry, M.; BASSENE, E.; BADJI, K.D., Contrubition à l'étude des 

plantes antipaludiques: Enquête ethnobotanique dans la région 

de Matam. 20015, Thése de doctorat, UCAD. 

Benlamdini A., Elhafian M., Rochdi A., and Zidane L., Étude 

floristique et ethnobotanique de la flore médicinale du Haute 

moulouya, Maroc, Journal.of Applied Biosciences, 2014. 

Blein R. et al, Agricultural potential in West Africa (ECOWAS). 
FARM, 2008.  



 

 

 

 Diouf et al. – Ethnobotanical Survey on the Plants Used in the Control of … 341 
 

 

Cissé I., Badiane B., Ngom S., Diop Y. MB., & Séne M., Usage 

des pesticides et risques sanitaires sur la production horticole 

de la zone des Niayes au Sénégal, Rev. Sn. res. Agric, 2008, 

Vol. 1 (3), 19-26. 

Dewailly E., Ayotte P., Bruneau S., Gingras S., Belles-Isles M., & 

Roy R., Susceptibility to infections and immune status in Inuit 

infant exposed to organochlorines, Environ Health Persp, 

2000, Vol. 108 (3), 205- 211. 

Diarra, A.; Diallo. B.; Implementation of regional pesticide 

policies: Report of the Case Study in Senegal. September 

2017. 

Diatta C.D., Gueye M., Akpo L.E., Medicinal plants used against 
dermatoses in the Baïnounk pharmacopoeia of Djibonker, 

Senegal. Journal of Applied Biosciences, 2013, (70): 5599-

5607. 

Diop, EL.H.M., Survey on knowledge, attitudes and practices 
related to the use of pesticides in the Niayes area. Thesis of 

Pharmacy, Dakar, 2015, n°212. 

DPS (Direction de la prévention de la Statistique), Situation 

économique et Sociale du Sénégal. Ed. DPS. 2003,197p. 

Eriksson M., Hardell L., Calberg M. & Akerman M., Pesticide 

exposure as risk factor of non-Hodgkin lymphoma including 

histopathological subgroup analysis, Int. J. Canc, 2008, Vol. 

123 (7), 1657-1663. 

Fall AS, Fall ST, Cisse I, Badiane AN, Diao MB, Fall CA. 

Characterization of the Niayes zone. In CITES Horticoles en 

Sursis? L'Agriculture Urbaine les Grandes Niayes au Sénégal. 

IDRC. 2001, http//idrc.ca/en/ev- 27906-201-1. 

MOMAGRI, Key Figures on Agriculture. 2016. 

Petrelli G. & Figa-Talamanca I., Reduction in fertility in male 

greenhouse workers exposed to pesticides, Eur. J. Epidemiol, 

2001, Vol. 17 (7), 675-677. 

Pousset, J.L., Plantes medicinales africaines (pharmacognosie), 

Tome 1, Masson, Paris, France. 1989, p 24, 156p. 

Rao et al, Effect of integration of Calotropis procera and Glomus 

fasciculatum on the management of Meloidogyne incognita 
infesting tomato. Nematologia Mediterranea, 1996, 24 (1): 59-

61. 

Svetaz L., et al. Value of the ethnomedical information for the 

discovery of plants with antifungal properties. A survey among 
seven Latin American countries. J Ethnopharmacol. 

2010;127:137-158. 

Yarou B.B., Bioefficiency of Ocimum spp. (Lamiaceae) for 

integrated pest management in vegetable crops. (PhD thesis). 
Gembloux Agro-Bio Tech, Liège University, Belgium. 

 

 



 

THIS PAGE INTENTIONALLY LEFT BLANK