Microbial priming of micro-propagated banana plantlets reduced effects of nematode and borer weevil (Cosmopolites sordidus) pests and enhanced plantlet growth

Nursery and field growth of micro-propagated banana plantlets is influenced by pests, nutrients and substrate quality. This study aims to evaluate the potential of locally produced microbial inoculant to reduce nematode and borer weevil (Cosmopolites sordidus) pest effects on micro-propagated banana plantlets and stimulate growth. The potential of locally produced microbial inoculant to reduce nematode and borer weevil pest effects on micro-propagated banana plantlets and stimulate growth was tested in nursery and field conditions. Plantlets were grown in polybags with three substrates (Soil + Coffee husk, Soil + Cocoa pod, and Soil + Empty palm fruit bunch) and two nutrient sources (chemical NPK fertilizer and microbial inoculant) relative to untreated control. Significant (P < 0.05) root necrosis occurred following nematode inoculation with/without borer weevil at planting or ten weeks after, with lower necrosis in pesticide and microbial inoculant than untreated control. Similarly, significant (P < 0.01) corm damage occurred following borer weevil inoculation with/without nematode at planting or ten weeks after, with lower corm damage in pesticide and microbial inoculant than untreated control. Although similar nursery growth of micro-propagated banana plantlets was observed across substrates, significant (P < 0.05) variation occurred between nutrient sources, with higher growth for NPK and microbial inoculant than untreated control. Similarly, field growth of banana plantlets was higher for NPK and microbial inoculant than untreated control (P < 0.05). These findings open up avenues for further investigation on role of locally produced microbial inoculant as promising option to reduce effects of nematode and borer weevil pests on micro-propagated banana plantlets and stimulate growth.