Use of AM fungus Rhizophagus irregularis and silicon dioxide nanoparticles for the management of Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani and growth of carrot

Abstract Impacts of AM fungus Rhizophagus irregularis and silicon dioxide nanoparticles (SiO2NPs) were observed on the disease complex of carrot (Daucus carota) caused by Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani. Use of R. irregularis alone together with SiO2NPs (0.10 mg ml−1) caused a significant increase in plant growth and photosynthetic pigments and reduce disease indices, galling and population of M. incognita. Use of R. irregularis resulted in a lesser plant growth and photosynthetic pigments than foliar spay of NPs. Use of R. irregularis with NPs spray was best for the management of disease complex. Leaf blight and root rot indices were 3 when fungal pathogen was inoculated alone and indices were 5 when pathogens were inoculated together. Use of R. irregularis/NPs with A. dauci/R. solani reduced indices to 2, indices were reduced to 1 when R. irregularis was used with SiO2 NPs. Root colonisation by R. irregularis was higher when alone but reduced in plants sprayed with NPs. Inoculation of test pathogens reduced colonisation by R. irregularis. Various studied attributes showed a significant correlation in principal components analysis. Significant management of disease complex may be achieved by the use of R. irregularis with SiO2 NPs.