Fungal biocontrol against Meloidogyne spp. in agricultural crops: A systematic review and meta-analysis

Root-knot nematodes are the most damaging nematode pest for worldwide agricultural production. Chemical control is the most popular method; however, the risks of chemical nematicides to environment and health have made some effective nematicides being removed from the use for some crops. Comprehensive literature searches were conducted to identify the most potential and consistent alternative strategies. Biological control has been a popular option with various, bacteria, fungi and other predators (e.g. mites). Among all the natural enemies of nematodes, nematophagous fungi are the most diverse and they use a variety of mechanisms to capture and kill nematodes. Many studies of nematophagous fungi have been published, but no cohesive analysis of these studies has been attempted. Therefore, a systematic review and meta-analysis were conducted to identify biocontrol fungi with the most consistent effects against root-knot nematodes. Pochonia spp., Trichoderma spp. and Paecilomyces spp. were the most studied fungal genera against root-knot nematodes. In general, most of the fungal genera controlled root-knot nematodes and improved plant growth and yield. However, the results showed that fungi alone cannot achieve a high level of suppression. In general, fungal bio-agents could reduce root-knot nematode population and damage levels by 45% compared to untreated conditions. Arthrobotrys spp. and Acremonium spp. were found to be comparatively more effective in root-knot nematode damage reduction than other species. The relationship of fungal biocontrol with soil properties could not be developed as the data were insufficient, highlighting the importance of reporting such data in future biological control studies.