Untitled

Abstract

This study is a contribution in the fight against early and late leaf spots (two fungal diseases) of peanut (Arachis hypogaea L.). The objectives of the study was to evaluate the antifungal effect of integrated treatment which composed of an aqueous extract of Lippia multiflora Moldenke leaves with a chemical fungicide (Chlorothalonil), alternately. The experiment was conducted in Gampêla district in Burkina Faso during the crop season 2016-2017. From 30 days after sowing (DAS), two varieties of peanuts, TS32-1 and B106, were sprayed five times, every 15 days, with the leaf plant extract (50 g dried leaves/1 l water) combined or not with Chlorothalonil. Marked effects on leaf spots were noticed from the first spraying, limiting the defoliation rate, the necrotic leaf area, and increasing pod and seed yield. Treatment means were compared using Student Newman-Keul test. Alternative treatments with Chlorothalonil fungicide reduced significantly the severity of diseases in the field. The maximum disease effect was observed on the untreated plot reaching the value of 6 in sensitive variety TS32-1. The integrated treatments, T2, T3 and T4 limited the disease at level 4 up to 90 DAS at last treatment. Among the alternative treatments, the highest pod and seed yields were observed with T4 (1519 and 408 kg ha -1 ) and T3 (1479 and 443 kg ha -1). This work confirmed the possibility to reduce the number of applications of fungicide in field by integrated treatments using aqueous extract of L. multiflora Moldenke leaves against leaf spots control. Therefore, the application of these plants extracts and Chlorothalonil in the control of leafs pots could lead to substantial yield increases for producers whilst ensuring safer conditions for consumers, producers and the environment.