Integrated Pest Management and Mycotoxin Reduction in Stored Yam in the Yam Belt of North Central Nigeria: From Ecology to Field Application

Yam is the primary staple crop and a major cultural symbol in the North Central geopolitical zone of Nigeria, yet stored yam losses from pest damage and associated mycotoxin contamination represent a critical food security and safety challenge. Current research addressing the ecological interaction between yam storage pests, fungal colonisation, and mycotoxin accumulation is fragmentary and has not produced integrated management solutions validated under field conditions in Nigeria's yam belt. This thesis reports a four-year integrated research programme developing and field-validating an Integrated Pest Management approach for simultaneous reduction of storage pests and mycotoxin accumulation in stored yam across North Central Nigeria. The programme included entomological surveys of yam storage pests in Benue, Kogi, and Kwara states using standardised monitoring traps, characterisation of the mycobiome of pest-damaged versus intact yam tubers using ITS metabarcoding, experimental evaluation of biological control agents (Beauveria bassiana and Trichoderma harzianum), physical storage modifications, and botanical repellents, followed by on-farm participatory trials with 240 yam farmers across twelve communities. Pest damage was the strongest predictor of mycotoxin accumulation, confirming the importance of pest management as a mycotoxin prevention strategy. Beauveria bassiana application combined with improved storage structure ventilation reduced total pest damage by 58 percent and mycotoxin prevalence by 41 percent in on-farm trials. The integrated approach was acceptable to 86 percent of participating farmers and economically viable at scale. The study provides the first evidence-based, field-validated Integrated Pest Management framework targeting co-occurring storage pest and mycotoxin challenges in Nigerian yam systems. Keywords: yam storage, integrated pest management, mycotoxins, biocontrol, North Central Nigeria.