PUB - Publikationen an der Universität Bielefeld

Root-knot nematodes cause global economic losses in a wide range of crops. We investigated the potential of seed coatings of the cover cropPhacelia tanacetifolia(Boraginaceae) when inoculated with the nematophagous fungusPochonia chlamydosporia(Hypocreales: Clavicipitaceae) to protect subsequently grown tomato plants from root galling caused by the root-knot nematodeMeloidogyne hapla(Tylenchida: Meloidogynidae). Therefore, seeds ofP. tanacetifoliawere coated withP. chlamydosporiablastospores and planted inM. hapla-infested pots. After 50 days of growth in infested soil,M. haplaeggs were extracted fromP. tanacetifoliaroots and quantified. Tomato plants grown in the remaining soil served as bioindicator ofM. haplainfestation as expressed by the gall index. Results showed that seed coating ofP. tanacetifoliawithP. chlamydosporia(290 ± 51 CFU per seed) reduced the number ofM. haplaeggs up to 95.6% in comparison to untreated controls.Pochonia chlamydosporiaas blastospore suspension (5·10⁸blastospores per 600 ml soil) reduced the number ofM. haplaeggs by up to 75.5%. Additionally, tomato plants grown for 50 days in substrates previously planted withP. tanacetifoliaseeds coated withP. chlamydosporiashowed a significantly lower gall index than plants grown in untreated pots. In conclusion, biological enhancement ofP. tanacetifoliaby seed coating withP. chlamydosporiasuccessfully reducedM. haplaand thus provides an additional tool in the management of this nematode. The method still has potential for further improvement such as increasing blastospore viability within the seed coating by optimized formulation technology.