The effects of organic amendments on the interactions between a nematophagous fungus Arthrobotrys oligospora and the root-knot nematode Meloidogyne mayaguensis parasitizing tomato plants

The aim of this study was to examine the effects of amendments with leaf bi omass on the development of tomato plants in a soil where root-knot nematod es (Meloidogyne mayaguensis) and/or a nematophagous fungus (Arthrobotrys ol igospora, strain ORS 18697) had been inoculated. Six origins of leaf biomas s were chosen: Acacia mangiumz, Acacia holosericea, Eucalyptus camaldulensi s, Casuarina equisetifolia, Azadirachta indica and Sorghum vulgare. These l eaf biomass types inhibited the development of the aerial parts of the toma to plants. This negative effect was not observed when the fungus was inocul ated. On the contrary, plant growth was stimulated. Moreover, the antagonis tic activity of Arthrobotrys oligospora was strengthened in the presence of ground leaf powder, especially that from Acacia holosericea. The effects o f phenolic compounds on fungal growth and predatory activity and on plant g rowth are discussed.