The weed Amaranthus palmeri is a host of Meloidogyne incognita in Uruguay

Abstract Amaranthus palmeri plants showing symptoms caused by root-knot nematode infection were detected in the municipality of Palmita, Soriano, Uruguay. Based on morphology, esterase phenotypes, and species-specific sequence-characterized amplified region (SCAR) sequences, the causal agent was identified as Meloidogyne incognita. Pathogenicity was confirmed using a modified version of Koch's postulates. To our knowledge, this is the first report of M. incognita infecting the roots of the weed A. palmeri in Uruguay.