Interaction of Meloidogyne incognita and Fusarium oxysporum on vegetable cowpea (Vigna unguiculata (L.) Walp

Abstract

Interaction between Meloidogyne incognita and Fusarium oxysporum in vegetable cowpea, Vigna unguiculata was studied at the Department of Nematology, College of Agriculture, Vellayani during 2019-2021. Highest cohabitation of both the pathogens was observed when M. incognita was inoculated seven days prior to F. oxysporum inoculation. Presence of nematodes prior to fungus caused early disease incidence (23 days) and increased severity of wilt disease. Highest reproduction factor (2.34) was observed in M. incognita alone followed by M. incognita+ F. oxysporum one week after nematode inoculation (1.79). Nematode reproduction and galling showed significant reduction in simultaneous inoculation of both pathogens compared to nematode inoculation one week prior to fungus inoculation. Plants inoculated with M. incognita + F. oxysporum at one week after nematode inoculation showed significant reduction in growth parameters viz. shoot length (55.40 per cent), fresh weight of shoot (63.44 per cent) and root (49.01 per cent) compared to unincoculated control plants. Lowest number of nodules/5g root (14.00) was recorded in plants treated with
M. incognita alone followed by M. incognita+ F. oxysporum one week after nematode inoculation (19.30).