Prevalence of Ginger Rhizome Rot (Pythium myriotylum) in Taraba State, North East Nigeria

Ginger (Zingiber officinale) is an important spice crop in Taraba State, where it is produced by smallholder farmers in the North East and sold to processors and traders across Nigeria. Rhizome rot caused by Pythium myriotylum is a persistent and economically destructive disease associated with significant production losses during the growing season. This study evaluated the prevalence of ginger rhizome rot and identified predisposing environmental and agronomic factors across five local government areas in Taraba State during 2023. Surveys were conducted in 50 ginger farms using randomised sampling, with rot symptoms assessed on both in-field plants and harvested rhizomes. Laboratory isolation and molecular characterisation confirmed P. myriotylum as the principal causal agent in 91 percent of diseased samples. Disease prevalence was 53 percent, with the highest incidence in farms established in waterlogged sites along river edges. Continuous monoculture of ginger for more than two consecutive years was significantly associated with elevated disease incidence. Analysis of inoculation trials revealed that wounds on rhizomes created during planting substantially increased rot susceptibility. Farmers were generally aware of the disease but lacked access to effective chemical control options. The study recommends integration of field drainage improvement, planting material hot water treatment, and crop rotation with non-host species to reduce rhizome rot impact in Taraba ginger farms. Keywords: ginger, rhizome rot, Pythium myriotylum, Taraba State, disease prevalence.