The asexual root-knot nematodes (RKNs) (Meloidogyne spp.) exemplified by Meloidogyne incognita are widespread and damaging pests in tropical and subtropical regions worldwide. Comparison of amplification products of two adjacent polymorphic regions of the mitochondrial genome using DNA extracts of characterized RKN strains, including 15 different species, indicate that several species are derived from the same or closely related female lineages. Nevertheless, M. javanica, M. enterolobii, M. incognita, and other key species could each be assigned unique mitochondrial haplotypes based on polymerase chain reaction fragment size and restriction cleavage patterns. M. arenaria isolates did not group as a single haplotype, consistent with other reports of diversity within this species. To test the utility of this assay, we characterized ethanol-preserved samples from 103 single-species isolates from four countries in sub-Saharan Africa (Benin, Nigeria, Kenya, and Tanzania). Mitochondrial haplotypes corresponding to M. javanica and M. incognita were the most prevalent. Samples from western Africa included several instances of M. enterolobii but this species was not detected in samples from East Africa. This protocol provides progress toward a standardized strategy for identification of RKN species from small, preserved samples and a rational starting point for classifying species present in regions where previous knowledge has been limited.

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This chapter describes the nematode parasites of root and tuber crops, including cassava (Manihot esculenta), yams (Dioscorea spp.), taro (Colocasia esculenta) and tannia (Xanthosoma spp.). Information is given on their distribution, biology and life cycle, symptoms of damage, environmental factors affecting parasitism, other hosts, disease complexes, economic importance, and management measures, which include host resistance, cultural, chemical, biological control methods.

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Nematodes are very diverse and parasitize various plants including vegetables, and their management is of concern. Biological control of nematodes provides an environmentally friendly management option and there are various micro-soil-borne organisms which can be considered for this purpose. The primary goal of this chapter is to provide a review on the progress made so far, in application of biological control agents in nematode management in vegetables, cereals, and root and tuber crops. This chapter will be divided into five (5) sections: (1) herbivore-induced plant volatiles, (2) root exudates and nematode control, (3) inhibitory metabolites in bacteria for nematode management, (4) fungi and symbiotic reprogramming in host cells, and (5) fungi antagonists of nematodes.

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Banana and plantain are popular fruits considered as major staple foods, and provide significant income to farming communities. A handicap to their development and production remains access to quality suckers. However, their diversity is still unknown in Benin. To assess the knowledge on the diversity of local varieties of both dessert banana and plantain at the community level, ethnobotanical surveys were undertaken using participatory research appraisal tools such as direct observations, group discussions and field visits from 119 interviewees living in 63 villages from 24 communes districts in Central and South of Benin. A total of 121 farmer-named banana and plantain varieties (83 vernacular names for banana and 39 others for plantains) were recorded and gathered into 58 differentiated varieties on the basis of the significance of the vernacular name relying on morphological traits and medicinal uses. Southern ethnic groups hold higher local varieties (H = 3.15 bits for the ethnic group Fon and H = 2.09 bits for Wemegbé) due to the high rainfall conditions favorable for the development of banana species than those from Central-Benin (H = 0.64 bits for the sociocultural group Mahi). The main constraints to these crop productions were drought (23.8% of responses), stealing of the whole bunch (19.0%), pests and diseases (14.3%), susceptibility to flood (9.5%) and pseudostem break by wind (7.8%). In situ and ex situ conservation should be undertaken to preserve the varieties cultivated by a few households on small areas defining their vulnerability status as well as those most commonly produced in large amounts.

Dans l'objectif de trouver un alternatif à l'endosulfan, l'efficacité du profenofos et de l'endosulfan a été étudié dans un dispositif de bloc aléatoire complet en station et en milieu réel. Sur station, le profenofos assure un contrôle, équivalent et parfois significativement supérieur (p < 0,001) à l'endosulfan, des populations des ravageurs comme Helicoverpa armigera, Earias spp, Pectinophora gossypiella, Cryptophlebia leucotreta. Le Fanga 500 EC (profenofos 750 g/ha) a été significativement supérieur (p < 0,05) à Callisulfan 350 EC (endosulfan 700 g/ha) pour le contrôle des populations de Aphis gossypii, Pectinophora gossypiella et Earias spp. Il en résulte une production de capsules vertes saines qui montre que le Calfos 500 EC (profenofos 750 g/ha) est équivalent aux différentes formulations d'endosulfan testées et parfois significativement meilleur (p < 0,01) au Thiofanex 350 EC (endosulfan 700 g/ha). A la récolte du coton graine, le profenofos procure un rendement significativement supérieur (p < 0,05) à l'endosulfan. En milieu paysan, aucune différence significative (p > 0,05) n'a été observée entre le Calfos 500 EC (profenofos 750 g/ha) et le Callisulfan 350 EC (endosulfan 700 g/ha) à la récolte du coton graine. Le profenofos peut être appliqué comme un alternatif à l'endosulfan en culture cotonnière au Bénin.