Exploring the disease severity by the interaction of Fusarium wilt and root knot nematode in tomato

Abstract

Fusarium wilt disease causes economic losses in all tomato growing areas, then it was converted to most devastating disease, when it combined infection with root knot nematode. Wilt infected samples were collected from tomato growing Madukarai area of Coimbatore district. Fusarium wilt pathogen was identified based on the morphological and molecular level. Root knot nematode was identified through post cuticular pattern. Then the interaction study was carried out in the pot culture under glass house condition. The present investigation focused on the role of root knot nematode and Fusarium pathogen in wilt incidence severity of tomato. The nematode fungal interaction was one of the contributing factor for increasing the wilt incidence and it was confirmed by the prior inoculation of root knot nematode (M. incognita) to the fungus (Fusarium oxysporum f. sp. lycopersici), the wilt incidence was recorded up to 87.50 % and vascular infection was high 53.20 % and 168 galls gram-1 of roots were also recorded then followed by 54.50 % wilt incidence, 44.60 % vascular infection and 111 galls gram-1 of roots were recorded in simultaneous application of fungus and nematode. The interesting fact is the 175 galls gram-1 of root was high in inoculation of nematode alone. The lowest wilt incidence 50.00 % was recorded and 34.90 % vascular infection in the prior inoculation of fungus to the nematode.