Antifungal potential of local plant extracts in the biological control of soil-borne diseases of tomato and eggplant in Daloa, Centre-West, Côte d'Ivoire

 Corresponding author: TRAORE Aboulaye Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution License 4.0. Antifungal potential of local plant extracts in the biological control of soil-borne diseases of tomato and eggplant in Daloa, Centre-West, Côte d'Ivoire SORO Sibirina *, TRAORE Aboulaye, KOFFI N’guessan Mathurin and TRAORE-OUATTARA Karidia Agricultural production improvement laboratory at the Université Jean LOROUGNON GUEDE, UJLoG, BP 150, Daloa, Côte d’Ivoire. World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 Publication history: Received 08 October 2025; revised on 22 November 2025; accepted on 24 November 2025 Article DOI: https://doi.org/10.30574/wjarr.2025.28.2.3663 Abstract Tomato and eggplant play a significant role in peri-urban agriculture. However, their production in the city of Daloa is limited by biotic diseases. This study aimed to evaluate the antifungal activity of six plant extracts against soil-borne fungal pathogens affecting tomato and eggplant. A microbiological study of the soil was conducted using a composite sample from the experimental plot. Two tomato cultivars (Petomech and F1 Cobra 26) and one eggplant cultivar (N'drowa) were used in the varietal sensitivity test. The first application of the plant extracts was carried out immediately after transplanting. Mancozeb was used as a reference control. Health monitoring of the tomato and eggplant plants involved assessing the incidence, severity and mortality rate. Samples taken from diseased plants were subjected to microbiological analysis. The collected data were analysed using Statistica 7.1 software. The results revealed the presence of four fungal genera on the plot: Botrytis sp, Trichoderma sp, Sclerotium sp and Aspergillus sp. The fungal genera isolated from the diseased plants were Phytophthora sp, Alternaria sp and Trichoderma sp. The biological control test showed that eggplant plants treated with Securidaca sp exhibited the greatest tolerance to disease, with a severity index of 2.1%. The F1 Cobra 26 variety, with a severity index of 5%, was less susceptible than the Petomech variety, with a severity index of 11.5%. Aqueous extracts of Securidaca sp and Solanum sp reduced mortality rates more effectively than synthetic fungicide. These aqueous extracts can therefore be recommended as an alternative for controlling soil-borne fungal diseases in tomato and eggplant. Keywords: Biofungicide; Essential oil; Aqueous Extract; Soil and Ivory Coast 1. Introduction Agriculture is one of the main sectors that contribute to the socio-economic development of populations. It employs over 40% of the global workforce, including over 52% in Africa and Asia [1]. Market gardening plays a significant role in human nutrition within this sector. In West Africa, it is one of the main components of urban and peri-urban agriculture, playing a key role in the economic development of cities [2]. Market gardening is a key component of many nutrition and poverty reduction programmes. In Côte d'Ivoire, market gardening is important for feeding the population and reducing poverty. Tomato (Lycopersicon esculentum Mill.) and eggplant (Solanum aethiopicum G.) are among the most widely produced crops in the country. They are almost indispensable ingredients in many Ivorian dishes and an important source of income for producers. However, despite the introduction of new production systems and the proliferation of plant protection products, national production of these vegetables remains insufficient to meet growing domestic demand. This could be due to the low productivity of these crops in certain parts of the country. These areas are characterised by diseases and pests that cause considerable damage to tomato and eggplant plants and fruits. This is the case in Daloa, where production is affected by soil-borne pathogens that cause various symptoms from the nursery stage through to harvest. Despite the development of pathogen-resistant cultivars, controlling soil-borne fungi in World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2312 plantations is limited to prophylactic measures and the use of synthetic pesticides [3 ; 4]. However, the use of synthetic chemical pesticides poses problems for both human health and the environment. Residues of active substances have been found in various horticultural products, sometimes exceeding the maximum residue limits (MRLs) established by the Codex Alimentarius of the European Union [5 ; 6]. Furthermore, the use of chemical pesticides promotes the emergence of resistant strains in agrosystems. To mitigate the impact of chemical control in agroecosystems, adopting biological control as an alternative method is crucial for safeguarding the health of producers and consumers, as well as protecting the environment. The aim objectif of this study is to find an efficacy plant extract to control the soil-borne fungal pathogens of tomato and eggplant. Specifically, the aim is to identify the mycopathogens responsible for the death of tomato and eggplant plants and to evaluate the fungicidal activity of aqueous extracts of Securidaca sp and Solanum sp species, followed by the essential oils of Ocimum canum and Ocimum gratissimum, on soil-borne fungal pathogens of tomato and eggplant in situ. 2. Materials and methods 2.1. Study site The work was carried out at Jean LOROUGNON GUEDE University in Daloa, a city located in the centre-west of Côte d'Ivoire. It is located at a latitude of 6°53' north and a longitude of 6°27' west. The city is the capital of the HautSassandra Region and covers an area of 15,200 km², with an estimated population of over 1 430 960 [7]. The climate of this Region is Sudano-Guinean, with four distinct seasons. The long rainy season runs from April to mid-July, while the short dry season runs from mid-July to mid-September. The short rainy season runs from mid-September to midNovember, and the long dry season runs from December to March. Temperatures range from an average of 24.65°C to 27.75°C during the dry and wet seasons. It is a humid tropical zone with dense forest vegetation [8]. The soil of Daloa is composed of granite from old Precambrian bedrock. The region's soils are mainly ferralitic. They are generally very deep with a high organic matter content. They are well suited to all types of agriculture [9]. The river system is dominated by the Sassandra River. The Lobo is this river's main tributary and the second most important watercourse [10]. Map of Côte d'Ivoire (A) and Map of Haut-Sassandra (B) Figure 1 Map of the study area [10] World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2313 2.2. Materials This study required a variety of equipment, including plant material, biological control agents, and both field and laboratory equipment. The plant material comprised two improved tomato cultivars (Petomech and F1 Cobra 26) and one eggplant cultivar (N'drowa). These cultivars were sourced from Callivoire in Daloa. The biological control agents were aqueous extracts from the leaves of Securidaca and Solanum species, as well as essential oils from Ocimum canum and Ocimum gratissimum. The synthetic fungicide Mancozeb was used as a positive control. The technical field equipment comprised tools for cultivating the soil and for measuring the height of the tomato and eggplant plants. Technical laboratory equipment included devices such as an autoclave, a magnetic stirrer, an oven, an electronic balance and an electron microscope. 3. Methods 3.1. Experimental setup The experimental setup consisted of four Fischer blocks, each with four completely randomised replicates (Figure 2). This was implemented on a 500 m² plot. The blocks were separated by one metre. Within each block, a total of 18 ridges were created, each measuring 250 cm in length and 70 cm in width. The distance between two ridges was one metre. Each ridge had a planting density of 10 tomato or eggplant plants arranged in rows of five, with 50 cm between each plant and between each row. 3.2. Production of tomato and eggplant nurseries The soil used for the nursery beds was taken from a low-lying area within the university grounds. It was then sterilised in a 25-litre metal bucket using steam for two hours. It was then left to cool for 24 hours in a basin, covered with a plastic sheet. The sterilised soil was divided into 10-dm² trays, with 100 tomato or eggplant seeds sown per tray. The nurseries were watered regularly, twice a day, for 21 days for the tomato and 30 days for the eggplants. 3.3. Production of aqueous extracts and essential oils 3.3.1. Production of aqueous extracts The Securidaca sp and Solanum sp leaves were harvested in Korhogo and Daloa, respectively, in Côte d'Ivoire. They were then left to dry at ambient temperature in a laboratory. The dried leaves were crushed and the resulting powder was sieved. One hundred grams of this sieved powder were macerated in one litre of distilled water for 24 hours. The mixture was blended for 15 minutes, then filtered and studied over three days at 40 °C. The dried aqueous filtrate, constituting the aqueous extract, was recovered and weighed to determine its yield. 3.3.2. Production of essential oils The fresh leaves of Ocimum gratissimum and Ocimum canum were harvested in Daloa in September. The essential oils were extracted from the leaves using hydrodistillation with a Clevenger-type device. For each extraction, 4 kg of leaves were weighed using an electronic balance before being placed in a pressure cooker containing 2 litres of water. The pressure cooker was placed on a hotplate set to 370 °C at the start of distillation. After 15 minutes of heating, the temperature was reduced to 225 °C. Extraction lasted for three hours. 3.4. Isolation of soil fungi A microbiological study of the soil in the experimental plot was conducted. For this analysis, a composite soil sample was taken from both diagonals. Soil samples were taken at a depth of 30 cm using a probe. The composite sample was then dried at room temperature in the laboratory. After drying, the soil was manually ground to obtain a fine powder. This fine powder was then used to prepare the aliquots. A stock solution was prepared by emulsifying 100 g of the powder in one litre of sterile distilled water. This solution was then used for a series of 1/10 dilutions on PDA culture medium. Four drops of the aliquot were placed equidistant from each other on the PDA medium in Petri dishes. The dishes were then sealed, dated, and incubated at 27 ± 2 °C until fungal colonies proliferated. 3.5. Transplanting and treatment of tomato and eggplant plants Tomato and eggplant plants, aged 30 and 37 days respectively, were transplanted onto the ridges within each block. The plants were transplanted according to the experimental design. The treatments were coded as follows: T0 for the blank control (distilled water); T1 for the aqueous extract of Securidaca sp; T2 for the aqueous extract of Solanum sp; T3 for the essential oil of Ocimum canum; T4 for the essential oil of Ocimum gratissimum; and T5 for the synthetic World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2314 fungicide mancozeb (positive control). The varieties were coded as follows: V1 for the 'N'drowa' eggplant variety; V2 for the 'Petomech' tomato variety; and V3 for the 'F1 Cobra 26' tomato variety. 3.6. Application of products to plants The aqueous extracts of Securidaca sp and Solanum sp were prepared by adding 100 g of powder to 1 litre of distilled water. The powders were weighed using an electronic balance, then mixed and homogenised in distilled water for 30 minutes. The essential oils of Ocimum gratissimum and Ocimum canum were diluted to 500 µL in 5 ml of Tween 20 per litre of distilled water. A micropipette was used to sample the oils. The synthetic fungicide Mancozeb was used at a concentration of 10 g/L. The plants were treated with 100 ml of solution containing the aqueous extracts, essential oils or synthetic fungicide. The solution was sprinkled at the base of each plant. This process was repeated three times, with an interval of 21 days between each application. 3.7. Maintenance and health monitoring of tomato and eggplant plants After transplanting, the plants were watered daily with tap water. This was done in the morning and evening until the harvest was finished. Weeds were removed from the plot regularly. Staking was carried out from the third week after transplanting until flowering. 3.8. Evaluation of health parameters on tomato and eggplants in situ 3.8.1. Incidence of diseases Attacks were counted by recording the number of diseased plants per treatment and per variety in the plot. Records were taken once a week until the plants flowered. The incidence was calculated using the following formula of [11]. With I: Incidence of attack; NBPm: Number of diseased plants per variety; NBP: Total number of plant per variety. 3.8.2. Severity index The disease severity index was determined using a 0–3 rating scale [12]. • 0: healthy plant • 1: slight yellowing of the plant • 2: severe yellowing of the plant • 3: dead plant The following formula was used to calculate the severity index per treatment and per variety: With • IS: Severity index; • Xi: Score assigned to the diseased plant; • ni: Number of diseased plants with the same score xi; • N: Total number of plants and • Z: Highest score. 3.9. Mortality rate The number of dead plants was assessed on the plot every fortnight. The mortality rate was calculated per treatment and per variety according to the formula below: Is = ∑ (Xi.ni) / (N.Z)*100 World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2315 TM: Mortality rate; NBPm: Number of diseased plants; NBTp: Total number of plants. 3.10. Identification of fungal isolates associated with symptoms in dead plants Isolations were carried out on PDA medium, which consisted of 20 g of agar, 5 g of potato flakes, and 5 g of glucose dissolved in 1 litre of distilled water. The medium was homogenised using a magnetic stirrer, then autoclaved at 1 bar and 121 °C for 30 minutes. The isolations were carried out using dead plants taken from the experimental plot. The roots were sectioned, rinsed with tap water, and then soaked in a 70% sodium hypochlorite solution for three minutes. The explants were then rinsed three times with sterile distilled water. The cleaned explants were then dried on blotting paper in a fume hood. Inoculation was then performed in the fume hood using Petri dishes containing frozen PDA medium. Four explants from the same plant were placed equidistant from each other in the same Petri dish. The Petri dishes were then sealed with parafilm, numbered and dated, and incubated at 27 ± 2 °C until the colonies had proliferated. Purification consisted of removing part of the mycelium from the outgrowth zone of the seeded Petri dish and transplanting it into the centre of a new Petri dish containing frozen PDA medium. The macroscopic characteristics of the fungal isolates were determined by staining the mycelium and observing its appearance on the PDA medium. Microscopic characteristics were determined using a photonic microscope. Observation focused on the mycelium, spore shape, conidia and conidiophores, according to the identification key [13]. 3.11. Statistical analysis of data The data was entered into an Excel spreadsheet. Statistica 7.1 software was then used to analyse the data statistically. The normality and the homogeneity of the data was respectively verified using the Shapiro–Wilk test and Bartlett test. The data were subjected to analysis of variance (ANOVA). The means were classified using the Newman-Keuls test (%). 4. Results 4.1. Fungi isolated from the soil Four fungal isolates were obtained from soil samples using the successive dilution technique. They were labelled I1, I2, I3 and I4 (Figure 2). Isolate I1 produced greyish-green mycelium with powdery aerial growth on PDA medium. The conidia were irregularly shaped and dark in appearance. I1 is a Botrytis sp and has a partitioned mycelium ending in clustered conidiospores. Isolate I2 is a Trichoderma sp. Initially, it has a cottony white thallus, which is covered by numerous green spores after a week. It has a septate mycelium with numerous round conidia. These conidia are produced at the end of phialides, which are borne by conidiospores. Isolate I3 exhibits the characteristics of Sclerotium rolfsii. It has a dense, milky-white thallus and grows rapidly on PDA medium. Its mycelium is septate and produces ovoid, yellowish-grey macrosclerotia measuring a millimetre in size. Aspergillus sp corresponds to isolate I4. Its hyphae are grey, septate and flaky. The sporocystophores are simple or branched, ending in a globular vesicle of variable size, from which various fruiting bodies grow. Botrytis sp (I1); Trichodema sp (I2); Sclerotium rolfsii (I3) and Aspergillus sp (I4) (x 400) Macroscopic aspects (A) and microscopic aspects (B). Figure 2 Morphology of fungi isolated from the soil of the experimental plot I3 I4 I1 A I2 B World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2316 4.2. Symptoms observed on tomato and eggplant plants The various organs of the tomato and eggplant plants showed symptoms of disease (Figure 3). Health monitoring identified three symptoms of disease on tomato plants. Seedling damping-off was observed on a tomato plant three days after transplanting. Young plants affected by damping-off died at the base of the stem. Affected seedlings died within 5 days. Apical wilt in tomato plants begins with the withering of a leaflet or leaf, progressing throughout the entire plant. The plant dies 3 days after widespread wilting. Plants affected by grey mould exhibit circular, damp patches on the leaflets that develop rapidly, causing the leaf blade to dry out. The leaf rots and the lesion spreads to the stem, turning it grey. Fruit affected by grey rot is covered in grey felting. The fruit wilts and loses its vigour. Apical necrosis of the fruit begins with the appearance of a black dot at the tip. This necrotic area then enlarges, deforming the fruit. Three types of symptoms have been observed on eggplant plants. These include yellowing of leaf margins, leaf blistering and leaf curling. Seedling blight on tomato plants (A); Apical wilt on eggplant plants (B); Grey rot on tomato plants (C); Apical necrosis on tomato fruit (D); Grey rot on tomato fruit (E); Blistering and curling of eggplant leaves (F and G). Figure 3 Symptoms of diseases observed on tomato and eggplant plants 4.3. Identification of fungal isolates associated with dead plants Microbiological analysis of the samples enabled three fungal genera to be isolated. (Figure 4). These three isolates were coded SF1, SF2 and SF3. On PDA medium, isolate SF1 (Phytophthora sp) produced white, cottony mycelium with a reddish centre. The sporocystophores are similar to the mycelium and have vesicles along the branches. Isolate SF2 is Alternaria sp and has a whitish mycelium for the first three days. After one week in the oven, the mycelium turns black. The hyphae of the mycelium are septate with monoseptate or biseptate spores. The SF3 isolate, Trichoderma sp, has greyish-green mycelium with powdery aerial felting. After 3 to 5 days, it produces dark, irregularly shaped sclerotia. The mycelium is compartmentalised and branched, ending in a conidiospore in the form of a cluster. 0, 5 m 0,5 m World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2317 Phytophtora sp (SF1); Alternaria sp (SF2) and Trichoderma sp (SF3). (X400) Macroscopic aspects (A) and microscopic aspects (B). Figure 4 Morphology of fungi isolated from diseased tomato and eggplant plants 4.4. Effect of plant extracts on tomato pathogen parameters Treated tomato plants were more resistant to disease than untreated plants, regardless of variety (Table 1). The results demonstrate that the incidence of attacks varied according to the treatments applied to the two cultivars. Petomech plants treated with the aqueous extract of Securidaca sp experienced a 25% reduction in the incidence of attack. Plants treated with the synthetic fungicide mancozeb showed an incidence of 35%. The highest incidence was recorded in untreated Petomech plants. Petomech plants treated with the aqueous extract of Securidaca sp had the lowest severity index of 15.5%, while those treated with Mancozeb had a severity index of 15.8%. The highest severity index, at 18.8%, was recorded in untreated Petomech plants. The lowest Petomech mortality rate of 22% was obtained by plants treated with the Securidaca sp extract, while plants treated with Mancozeb had a mortality rate of 52%. The highest mortality rate (60%) was recorded in untreated Petomech plants (Table 1). The lowest incidence, 21.33%, was observed in F1 Cobra 26 plants treated with an aqueous extract of Solanum sp. An incidence of 36.33% was observed in F1 Cobra 26 plants treated with Mancozeb. The highest incidence, at 85%, was recorded in untreated F1 Cobra 26 plants. The lowest severity index, 0.5%, was obtained in F1 Cobra 26 plants treated with the aqueous extract of Solanum sp, while the severity index was 8.2% in F1 Cobra 26 plants treated with Mancozeb. The highest severity index, 18.7%, was recorded in untreated plants. The lowest mortality rates of 17% and 18%, respectively, were obtained by F1 Cobra 26 plants treated with the aqueous extracts of Solanum sp and Securidaca sp, while F1 Cobra 26 plants treated with Mancozeb recorded a mortality rate of 22%. The highest mortality rate of 22% was obtained in untreated F1 Cobra 26 plants. Table 1 Tomato cultivars' sensitivity Varieties and treatements Incidence (%) Severity index (%) Mortality rate (%) V2T0 66.67 18.8 60 V2T1 25.00 11.5 22 V2T2 26.67 14.5 27 V2T3 30.00 12.2 38 V2T4 32.00 12.0 33 V2T5 35.00 15.8 52 V3T0 85.00 18.7 57 V3T1 26.00 6.7 18 V3T2 21.33 5.0 17 World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2318 V3T3 34.67 6.0 18 V3T4 29.00 10.5 33 V3T5 36.33 8.2 22 Values in the same column followed by the same letter are not significantly different according to the Newman-Keuls test at p < 0.05. V2T0: Untreated Petomech plants; V2T1: Petomech plants treated with Securidaca sp aqueous extract; V2T2: Petomech plants treated with Solanum sp aqueous extract; V2T3: Petomech plants treated with O. canum essential oil; V2T4: Petomech plants treated with O. gratissimum essential oil and V2T5: Petomech plants treated with Mancozeb. V3T0: Untreated F1 Cobra 26 plants; V3T1: F1 Cobra 26 plants treated with Securidaca sp aqueous extract; V3T2: F1 Cobra 26 plants treated with Solanum sp aqueous extract; V3T3: F1 Cobra 26 plants treated with O. canum essential oil; V3T4: F1 Cobra 26 plants treated with O. gratissimum essential oil; V3T5: F1 Cobra 26 plants treated with Mancozeb. 4.5. Effect of plant extracts on eggplant pathogen parameters The treated plants were more resistant to disease compared to the untreated plants (Table 2). The lowest incidence (8.33%) was recorded for N'drowa plants treated with the aqueous extract of Securidaca sp, while plants treated with Mancozeb recorded an incidence of 36.67%. The highest incidence, at 78.33%, was recorded in untreated N'drowa plants. The lowest severity index, at 2.1%, was recorded in N'drowa plants treated with the aqueous extract of Securidaca sp, while plants treated with Mancozeb had an index of 6.2%. The highest severity index, at 12.2%, was recorded in untreated N'drowa plants. There was no mortality recorded in N'drowa plants treated with the aqueous extract of Securidaca sp, whereas N'drowa plants treated with the aqueous extract of Solanum sp had a mortality rate of 4%. The mortality rate in plants treated with Mancozeb was 17%. The highest mortality rate (23%) was obtained in untreated N'drowa plants. Table 2 Eggplant sensitivity Varieties and treatements Incidence (%) Severity index (%) Mortality rate (%) V1T0 78.33 12.2 23 V1T1 8.33 2.1 0 V1T2 26.67 2.6 4 V1T3 20.00 3.3 7 V1T4 22.33 4.3 8 V1T5 36.67 6.2 17 Values in the same column followed by the same letter are not significantly different according to the Newman-Keuls test at p < 0.05. V1T0: Untreated N'drowa plants; V1T1: N'drowa plants treated with aqueous extract of Securidaca sp; V1T2: N'drowa plants treated with aqueous extract of Solanum sp; V1T3: N'drowa plants treated with essential oil of O. canum, V1T4: N'drowa plants treated with essential oil of O. gratissimum and V1T5: N'drowa plants treated with Mancozeb. 5. Discussion A preliminary study of the soil microflora of the experimental plot revealed a variety of fungal isolates. Four fungal genera were isolated from the plot soil: Botrytis sp, Trichoderma sp, Sclerotium sp and Aspergillus sp. These soil fungi are phytopathogenic. In the absence of favourable conditions, their presence in the soil would serve as a means of conservation. This corroborates the findings of [13], who also detected fungi in samples from various tomato production areas in Côte d'Ivoire. Microbiological analysis of samples taken from diseased tomato and eggplant plants revealed the presence of Phytophthora sp, Alternaria sp and Botrytis sp, with the exception of Trichoderma sp, which is an hyperparasite. All of the isolates identified are pathogenic to tomato and eggplant. This result reflects the susceptibility of these crops to the various identified pathogens. This susceptibility is thought to be due to the inefficiency of the defence systems that these crops have evolved to combat fungal attacks. Phytopathogenic fungi are believed to possess enzymatic molecules that allow them to bypass the defence systems of various plant species. The products applied had no effect on the mycopathogens isolated from the plants. These mycopathogens were resistant to the products applied. These results are consistent with those of [14 ; 15], who demonstrated that the efficacy of an antifungal extract can vary depending on the fungal strain. They demonstrated that the aqueous extract of Xylopia aethiopica (Dunal) A. Rich. (Annonaceae) inhibits the germination of Colletotrichum destructivum spores and the growth of its colonies. However, no fungicidal effect was observed for this same aqueous extract on Sclerotium rolfsii, in contrast to the essential oil, which was highly World Journal of Advanced Research and Reviews, 2025, 28(02), 2311-2321 2319 effective against the same fungus. The presence of Botrytis sp in dead plants could be explained by its diverse habitat. It is a polyphagous fungus that can spread on plant debris. The plant extracts had different effects on the sensitivity of tomato and eggplant plants. This difference in efficacy could be explained by the nature of their physicochemical composition. This composition varies from one plant species to another, which could explain this difference in efficacy. Aqueous extracts reduced the incidence of fungal attacks more in the three cultivars. The effectiveness of the aqueous extracts may be due to the fact that they contain residues that remain in contact with the treated plants for longer. These results corroborate those of [14], who demonstrated that aqueous extracts offer greater protection to tomato plants against fungal attacks. These results also align with those of [16], who demonstrated that Xylopia aethiopica extracts mitigate tomato disease incidence in Côte d'Ivoire. Essential oils were less effective in reducing the incidence of attacks. This is thought to be due to the nature of the emulsifier used and the persistence of the oils at the base of the treated plants. Essential oils are rich in phenolic compound [17]. They are also highly volatile, and application at high temperatures reduces their effectiveness at the base of the plants [18].The severity of fungal diseases in tomato and eggplant varied according to the treatments. The lowest indices were obtained with the aqueous extract of Securidaca sp at N'drowa and Petomech, and with the aqueous extract of Solanum sp at F1 Cobra 26. All of the aqueous extracts were more effective than the positive control (Mancozeb). The efficacy of the aqueous extracts compared to synthetic fungicides can be attributed to their high content of phenolic compounds, which stimulate plant defence mechanisms. This includes strengthening cell walls through lignin deposition or defence protein synthesis [19]. Previous studies have demonstrated the ability of plant extracts to protect cultivated plants against attacks by microorganisms. Alchornea cordifolia (Schum. and Thonn.) and Mezoneuron benthamianum (Baill.) extracts are rich in phenolic compounds, including alkaloids, flavonoids, and saponins. They also contain amides, which are products of organic matter decomposition [20]. The mortality rate of tomato and eggplant plants varied according to the treatment applied. No mortality was observed at N'drowa with the aqueous extract of Securidaca sp, in contrast to the results obtained with the essential oils. The lowest mortality rate was obtained with the aqueous extract of Solanum sp, indicating that aqueous extracts improve eggplant tolerance to fungal attack. Regarding tomato cultivars, the lowest mortality rate was recorded with the aqueous extracts of Securidaca and Solanum, and this rate was lower in the F1 Cobra 26 variety than in the Petomech variety. These results suggest that the F1 Cobra 26 variety is less susceptible to fungal attack than the Petomech variety. This difference in susceptibility could be explained by the genetic makeup of the different tomato cultivars. The F1 Cobra 26 variety may naturally secrete substances that inhibit the development of fungi that attack different cultivars. 6. Conclusion Studying the soil microflora of market garden crops at the Université Jean LOROUGNON GUEDE (UJLoG) in Daloa revealed its fungal diversity. Six pathogenic fungal isolates and one hyperparasite of the Trichoderma genus were found in the soil and in dead tomato and eggplant seedlings. Mortality rates were higher for tomato than eggplant in the soil. Plant extracts used to control mycopathogens in tomato and eggplants showed that aqueous extracts were more effective than essential oils or the synthetic fungicide Mancozeb. The aqueous extract of Securidaca sp was the most effective biofungicide in reducing the incidence and mortality rates of tomato and eggplant plants. Their efficacy compared with the positive control (Mancozeb) makes these aqueous extracts an alternative to synthetic chemical pesticides. They could therefore be recommended for use on vegetable crops. However, further efficacy tests will need to be carried out on farms. Compliance with ethical standards Acknowledgments We thank the Agricultural Production Improvement Laboratory of the University Jean LOROUGNON GUEDE of Daloa for the equipment. We would also like to thank the director of this laboratory, Professor AYOLIE Koutoua, for his collaboration. Disclosure of conflict of interest The authors declare no conflicts of interest regarding the publication of this paper.