Meloidogyne incognita and Rotylenchulus reniformis and Associated Soil Textures from Some Cotton Production Areas of Texas

  • J. L. Starr
  • C. M. Heald
  • A. F. Robinson
  • R. G. Smith
  • J. P. Krausz


The incidence of Meloidogyne incognita and Rotylenchulus reniformis on cotton was determined in 1989-92 from 1,089 soil samples collected from 31 counties that account for nearly 60% of the 2.2 million hectares planted to cotton in Texas. Meloidogyne incognita was commonly found in the Southern High Plains and Brazos River Valley regions of Texas (57% and 34%, respectively, of samples) but was found in less than 8% of samples from the Central Blacklands, Coastal Bend, Low Plains, or the Upper Gulf Coast regions. Rotylenchulus reniformis was widely distributed in the Brazos River Valley (24% of samples) and found occasionally in the Upper Gulf Coast (8% of samples). Meloidogyne incognita was found only rarely in soils with greater than 40% clay content, whereas Rotylenchulus reniformis was frequently found in finely textured soils but was less common in soils with greater than 40% sand content. In samples infested with M. incognita or R. reniformis, population densities of these species were at least 10-fold greater than population densities of other plant-parasitic species present in the sample. Root-knot and reniform nematodes were not found together in high population densities ( 100 individuals/500 cm³) in the same sample. Key words: cotton, Gossypium hirsutum, incidence, Meloidogyne incognita, nematode, reniform nematode, root-knot nematode, Rotylenchulus reniformis, soil texture, survey.