Effet de L’hyptis (Hyptis suaveolens), du Neem (Azadirachta indica), du Vernonia (Vernonia amygdalina), et de L’amarante (Amaranthus sp.) sur les nematodes A Galles (Meloidogyne spp.) en cultures Maraicheres

Abstract

Root knot nematodes (Meloidogyne spp.) are among the most damaging pests to vegetables cropping. In order to find alternative means for chemical control of these parasites, the nematicidal effect of aqueous extracts from fresh and dried leaves, as well as stems and roots of 4 local plants varieties : hyptis (Hyptis suaveolens), neem (Azadirachta indica), vernonia (Vernonia amygdalina), and amaranthus (Amaranthus sp.), on infective juveniles (J2) of Meloidogyne spp. was evaluated in Petri dishes, using 4 concentrations (5, 10, 15 et 20 %) of each extract and tap water (0 %), as a control. The plant extracts induced nematode mortality rates ranging from 20 to 95 % 6 days after exposure. The effect of extracts was found to be related to plant species used, and varied significantly (p 0.05) with plant organ, as well as with extracts concentrations. At all concentrations, nematode mortality rates due to leaf extracts were greater (p 0.05) than those due to stem or root extracts of the same plant. Fresh leaf extracts from neem induced the highest mortality rate (95 %, p 0.05) at a concentration of 20 %, followed by fresh leaf extracts from vernonia (86,6 %, p 0.05) in the same period. These results show that neem, vernonia, hyptis and amaranthus had a good potential for use in an integrated management of Meloidogyne spp.

Keywords: Meloidogyne spp., plant with nematicidal effect, aqueous extract, vegetables, Benin

Agronomie Africaine 24 (3) : 209 - 218 (2012)