Efficacité des plantes médicinales dans la lutte contre ootheca mutabilis sahlb. (Chrysomelidae)‎ en champ de niébé (Vigna Unguiculata (L.)‎ Walp.)‎ en rd du Congo

Abstract EN

This study was conducted during the main crop growing season (September 2009 to February 2010) at 2 sites (one based in rural area: Mpiana site; another one based at the agricultural research station of the INERA: Gandajika site) in Kasaï-Oriental province.

The experimental trials were conducted following a split-plot experimental design with three replicates.

These trials were conducted to assess the efficacy of aqueous extracts of leaves of some medicinal plants (Azadirachta indica, Tephrosia vogelii Hook., Carica papaya L.) in reducing/suppressing populations build up of Ootheca mutabilis.

Cowpea was sprayed with aqueous extracts (individually or mixed) of these three plants from 14 to 67 days after sowing of cowpea.

More than 50% of cowpea leaves were found damaged (defoliated) by Ootheca mutabilis at flowering.

Attacks during flowering and pod setting periods led to a high yield loss of cowpea of above 50%.

Results from this study indicated also that aqueous extracts of the three medicinal plants (at any dose of application) tested did not reduce significantly (P>0.05) the population density of the pest.

For all cowpea varieties tested, (independently of all treatments applied at 14, 28, 35 and 42 days post emergency of cowpea), the average number of damaged leaves oscillated between 7.67 and 10.17% for Diamant variety, between 8.67% and 15% for variety IT82D-889 and between 5.33 and 10.17% for the variety Muyaya.

The insect mortality was lower than expected (less than 100 insects were counted dead from more than 1000 counted per experimental plot).

In brief, the aqueous extracts of medicinal plants tested were not able to control the field population densities of the cowpea pest Ootheca mutabilis