Interactions of nematodes with the fungal Panama wilt disease of banana and its management

Abstract

Investigations were undertaken in pots (30 × 20 × 18 cm) filled with sterilized potting mixture consisting of red soil:sand:FYM (2 : 1 : 1 v/v) to assess a possible interaction between Panama wilt of banana caused by Fusarium oxysporum f.sp. cubense (Foc) and the spiral nematode Helicotylenchus multicinctus. The effects on the nematode population and severity of fungal disease expression of dip treatments of banana suckers with the fungicide carbendazim or the insecticide monocrotophos, and soil application of neem seed cake, carbendazim or bio-control agents Trichoderma viride and Pseudomonas fluorescens were also investigated. The results revealed a negative interaction between the fungus and the nematodes. Nematode populations and lesion indices were highest when each pathogen was inoculated alone and lowest when inoculation of Foc followed that of the nematode. The management trial indicated that dip treatment of banana suckers for 45 minutes in a combination of monocrotophos 36 EC 0.15% and carbendazim 0.2% resulted in maximum reduction of nematode population, lesion index and disease incidence.