Well known microbial plant growth promoters provoke plant growth suppression and increase chili pepper wilt caused by the root pathogen Phytophthora capsici

Abstract Microbial plant growth promoters (MPGP) are known to improve crop nutrition and root health. Here we examined the effects of individual combined inoculation chili pepper (variety Camino Real) with Rhizophagus irregularis (isolate BEG87) a commercial product Azospirillum brasilense on biocontrol against oomycete pathogen Phytophthora capsici CH11). In greenhouse pot experiment, unfertilized ten-week-old plants R. A. were confronted P. capsici, four weeks later harvested scored for disease severity. Surprisingly, both MPGP not only decreased growth, but also promoted rot caused by . This increased severity in mycorrhizal was further corroborated second experiment inert substrate mineral fertilization. conclusion, may cause suppression plants, increase capsici.