The root-knot nematode Meloidogyne graminicola has become a serious threat to rice production as a result of the cultivation changes from transplanting to direct seeding. The nematicidal activity of Aspergillus welwitschiae have been investigated in vitro , and the disease control efficacy of the active compound has been evaluated under greenhouse and field conditions. Results: The active compound αβ-dehydrocurvularin (αβ-DC), isolated by nematicidal assay-directed fractionation, showed

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... ant nematicidal activity against M. graminicola , with an median lethal concentration (LC 50 ) value of 122.2 μg mL −1 . αβ-DC effectively decreased the attraction of rice roots to nematodes and the infection of nematodes and also suppressed the development of nematodes under greenhouse conditions. Moreover, αβ-DC efficiently reduced the root gall index under field conditions. Conclusion: To our knowledge, this is the first report to describe the nematicidal activity of αβ-DC against M. graminicola . The results obtained under greenhouse and field conditions provide a basis for developing commercial formulations from αβ-DC to control M. graminicola in the future.