Effet antifongique de deux extraits de plantes sur les agents pathogènes identifiés sur des fruits de l’anacardier (Anacardium occidentale L.) au Nord Cameroun

Abstract

L’anacardier (Anacardium occidentale L.), importante culture de rente, est confrontée à la menace de nombreux pathogènes qui entravent sa productivité au Cameroun. Dès lors, cette étude se propose de déterminer le potentiel d’une lutte biologique à base d’extraits végétaux sur les champignons pathogènes identifiés sur des fruits prélevés dans le bassin de la Benoué. Pour atteindre ces objectifs, l’identification des agents pathogènes des fruits, des tests de pathogénicité et l’évaluation de l’effet antifongique in vitro et in vivo des extraits de piments et de neem ont été effectués. Les résultats ont montré que ces fruits abritent une diversité d’espèces fongiques dont les principales sont Colletotrichum gloeosporioides, Oïdium anacardii, Fusarium solani, Aspergillus niger et Phytophthora sp. Les tests de pathogénicité ont produit les symptômes des maladies observées sur le terrain. L’huile de neem et les extrait de piment ont inhibé totalement la croissance de C. gloeosporioides, O. anacardii et A. niger aux doses respectives de 7,5% v/v et 75 mg/ml. Cependant, l'huile de neem s'est avérée plus efficace. Ces résultats représentent des sources d'information précieuses pour l’implémentation d'une stratégie de lutte intégrée contre les agents pathogènes de l’anacardier à l’origine de la baisse de sa productivité, affectant ainsi son potentiel économique.
 English Title: Antifungal effect of two plant extracts on pathogens identified on fruits of Cashew tree (Anacardium occidentale L.) in North Cameroon
 The Cashew tree (Anacardium occidentale L.), an important cash crop, is challenged by the proliferation of pathogens that affect its productivity in Cameroon. Therefore, this study aims to determine the potential of a biological control based on plant extracts on pathogenic fungi identified on fruits collected in the Benoué basin. To achieve these objectives, identification of fruit pathogens, pathogenicity tests and evaluation of the in vitro and in vivo antifungal effect of chilli and neem extracts were carried out. The results showed that these fruits harbour a diversity of fungal species, of which the main ones are Colletotrichum gloeosporioides, Oïdium anacardii, Fusarium solani, Aspergillus niger and Phytophthora sp. The pathogenicity tests have generated the symptoms of the diseases observed in the field. Neem oil and chilli extracts completely inhibited the growth of C. gloeosporioides, O. anacardii and A. niger at doses of 7.5% v/v and 75 mg/ml respectively. However, neem oil proved to be more effective. These results represent valuable sources of information for the implementation of an integrated pest management strategy against cashew pathogens that impede the productivity of the tree, thereby affecting its economic potential.

Antifungal Potential of Three Plant Extracts in the Control of Some Major Fungi Associated with Cashew Seeds (Anacardium occidentale L.)

“…The percentages of sporulation inhibition of the different fungi depended on the concentration applied; the plant and the type of extracts (Tables 4 and 5). Aqueous extracts of L. camara at the concentration of 28 mg/ml, inhibited 100% [12,13,21], who showed that cashew fruits harbour a diversity of fungi that could be transmitted to the seeds. This fungal diversity is thought to be due to the fact that cashew seeds are an important source of carbohydrate for fungi species or they appear due to poor seed storage conditions.…”

“…In Cameroon, several works have been reported on the identification of the main pathogens of cashew fruits [20,21]; the observation is that there is no data on seed-borne fungi of cashew. However, such information is necessary for the development of effective control measures against these fungal species.…”

Inventory and Management of Fungi Associated with Banana Plant through the Use of <i>Allium ampeloprasum</i> and <i>Cymbopogon citratus</i> Extracts

“…The works of [12] are reported that aqueous and ethanol extracts of Cymbopogon citratus inhibit the development of Colletotrichum kahawae, causal agent of anth-racnose berry coffee. Extract of Allium ampeloprasum possess antifungal potential against Aspergillus niger, Penicillium italicum, Botrytis cinerea, and Trichoderma harzianum [13]. The aim of this study is to ameliorate banana production through the control of banana plant diseases by the use of plant extracts.…”

In vitro activities of fungicides based of plants essentials oils (NECO, ASTOUN and FERCA) and phosphorous acid on Phytophthora katsurae (Pythiaceae), causal agent of the premature nut fall and the heart rot of the coconut tree, in Côte d’Iv

“…Facing this situation, the search for other means of control (Ahouansou et al, 2019) that are both effective and respectful to the standards on the local Ivorian market is necessary. To this end, several research works using natural substances such as extracts from local plants have made it possible to fight effectively against several types of plant pests (Kassi et al, 2014 ;Yala et al, 2016;Camara et al, 2017 ;Fofana et al, 2020;Nyaka et al, 2021). This has led to the formulation of many biopesticides (Camara et al, 2007;Camara et al, 2010;Yala et al, 2017;Akantetou et al, 2020).…”