Interaction Between Meloidogyne incognita and Fusarium oxysporum in Causing Disease Complex on Tomato

Abstract

The interaction between root-knot nematodes and soil-borne fungal pathogens often results in severe disease complexes that significantly reduce crop productivity and plant health. The present study investigated the interaction between Meloidogyne incognita and Fusarium oxysporum in causing disease complex on tomato under controlled and field conditions. Tomato plants were inoculated individually and in combination with the nematode and fungal pathogen to evaluate their effects on disease development, plant growth, and pathogen aggressiveness. Observations were recorded on root galling, vascular discoloration, wilt severity, plant height, biomass reduction, and yield-related parameters. The results demonstrated that combined inoculation of M. incognita and F. oxysporum caused significantly greater disease severity compared to single pathogen infections. Plants exposed to both pathogens exhibited extensive root galling, severe wilting, chlorosis, vascular browning, and substantial reduction in plant growth and vigor. The presence of M. incognita enhanced fungal infection by creating wounds and physiological stress in root tissues, thereby facilitating fungal colonization and disease progression. Similarly, fungal infection weakened plant defense mechanisms and increased susceptibility to nematode infestation. Synergistic interactions between the two pathogens resulted in accelerated symptom development and greater yield losses in tomato plants. Environmental conditions such as soil moisture and temperature further influenced the severity of the disease complex. The findings highlight the importance of understanding pathogen interactions in tomato production systems and emphasize the need for integrated disease management approaches targeting both nematodes and fungal pathogens simultaneously.