Agro-industrial waste and a nematicidal substance therein (triethyl phosphate) are effective against Meloidogyne incognita of bananas

Meloidogyne are a group of plant-parasitic nematodes that cause very large yield losses of agricultural crops globally. Banana plants are susceptible to Meloidogyne, which are mainly controlled by chemical nematicides. However, these harm the environment and human health, and their use is thus being restricted. This study developed novel sustainable practices to control root-knot nematodes in banana production. Chicken manure and cassava ethanol wastewater are common agro-industrial wastes. After fermentation, both fermentation broths reduced Meloidogyne incognita infection by killing the second-stage juvenile nematodes and inhibiting egg hatching. The fermentation broths also decreased root galls and the soil nematode density. We used gas chromatography-mass spectrometry to identify triethyl phosphate as the nematicidal compound; this inhibited egg hatching and promoted juvenile mortality in Meloidogyne incognita. In terms of nematode control, both fermentation broths provided the nutrients necessary for banana growth and improved the nutrient contents of banana plants. Both fermentation broths (2-10%) and triethyl phosphate (0.5-4.0 mM) have no effects on nontarget organism Caenorhabditis elegans. Collectively, our results contribute a safe strategy for nematode management, recycling of agro-industrial waste, and improving the sustainability of banana production.