Influence de la rotation culturale, de la fertilisation et du labour sur les populations de nématodes phytoparasites du sorgho (Sorghum bicolor (L.) Moench)

Abstract

Influence of crop rotation, fertilization and tillage on populations of plant parasitic nematodes of sorghum (Sorghum bicolor (L.) Moench). The soil nematodes of three long-term trials (1960, 1980 and 1990) representing the production of sorghum (Sorghum bicolor (L.) Moench) under different agricultural practices (rotation, tillage and fertilization) in the Center West of Burkina Faso, have been explored in the wake of the harvest during the agricultural season 2007/2008. The objective was to identify these nematodes and to study the influence of agricultural practices on this nematofauna. Nematodes were extracted by the method of Seinhorst elutriator. Plant-parasitic nematodes identified are Pratylenchus brachyurus, Tylenchorhynchus martini, Helicotylenchus multicinctus, Scutellonema Caveness, Criconemoides curvatum, Telotylenchus indicus and Xiphinema sp. The first three species represent approximately 98% of individuals surveyed. On the first site, the treatments involving mineral fertilizer and recycling of sorghum straw were favorable for the control of nematodes instead of treatments involving manure. As for rotations, monoculture of sorghum was more infested by nematodes than the rotations sorghum – cowpea and sorghum – cotton. On the second site, the nitrogen has increased of infestation by the two major nematodes in comparison to treatments without nitrogen, with the exception of treatment with anaerobic compost incorporation. On the third site, deep plowing has been unfavorable to the main nematode sorghum compared to shallow tillage. The nematofauna in fallow was more diversified than in cultivated sites and P. brachyurus, the main nematode related to sorghum has fallen sharply in fallow.

Keywords

• Sorghum bicolor
• plant nematodes
• rotation
• tillage
• fertilization
• fallow
• Burkina Faso