Natural occurrence of fungal egg parasites of root-knot nematodes, Meloidogyne spp. in organic and integrated vegetable production systems in Spain

A survey was conducted to assess the biodiversity and frequency of infection of fungal egg parasites of Meloidogyne spp. and relate results to soil properties in organic and integrated vegetable production in Spain. Forty sites were sampled at the end of the cropping cycle, 30 under integrated and ten under organic production. Fungal egg parasites were isolated from all organically managed sites and from 73 % sites under integrated production. Species richness and Shannon–Wiener index did not differ between production systems but the percentage of fungal egg parasitism did, as well as soil properties. Percentages of egg parasitism higher than 40 % were found in five and three sites under organic and integrated production, respectively. In all these sites, Pochonia chlamydosporia was present alone or co-occurring with other fungal species. The relative frequency of P. chlamydosporia was positively related to the percentage of parasitism in both production systems.