Preplanting Inoculum Densities of Root-Knot Nematode Related to Carrot Yield in Greenhouse. C. S. Huang, Associate Professor, Laboratório de Fitopatologia, Departamento de Biología Vegetal, Universidade de Brasília. J. M. Charchar, CNP-Hortaliças, EMBRAPA, Brasília-DF, Brazil. Plant Dis. 66:1064-1066. Accepted for publication 2 March 1982. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-1064.

Pot experiments showed that preplanting infestation of Meloidogyne incognita at densities exceeding 230 juveniles + 2,300 eggs per liter of soil drastically suppressed marketable carrot (Daucus carota cv. Nantes) yield. The nematode rendered carrot unmarketable by causing constrictions, digitations, and crackings on the taproots. Only young plants were vulnerable to the nematode-related deformities. At preplanting inoculum densities less than 2,300 juveniles + 23,000 eggs per liter of soil, the nematode did not affect the total weight of the taproots produced.

Keyword(s): crop loss of carrot.