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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #164672
Title: RELATIVE HOST STATUS OF SELECTED WEEDS AND CROPS FOR MELOIDOGYNE INCOGNITA AND ROTYLENCHULUS RENIFORMIS

Author
item Davis, Richard
item Webster, Theodore

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2004
Publication Date: 4/1/2005
Citation: Davis, R. F., Webster, T. M. 2005. Relative host status of selected weeds and crops for Meloidogyne incognita and Rotylenchulus reniformis. Journal of Cotton Science. 9:41-46.

Interpretive Summary: Plant-parasitic nematodes which damage crops can also reproduce on weeds, thereby reducing the efficacy of nematode-suppressive crop rotations. However, the amount of reproduction by nematodes which damage cotton that occurs on weeds common in the major Southeastern crops is not known. This study documented the amount of southern root-knot nematode and reniform nematode reproduction on common southeastern weeds: total reproduction and reproduction relative to cotton were measured. Final root-knot nematode egg counts on the plants tested ranged from 0% to 193% of the number on cotton in one trial and from 0% to 407% in the other trial, and final reniform egg counts ranged from 0% to 105% in one trial and from 0% to 454% in the other trial. Only prickly sida consistently allowed more root-knot reproduction than cotton, though ivyleaf morningglory supported more reproduction in one trial. Smallflower morningglory was a moderate host relative to cotton, whereas yellow and purple nutsedge, pigweed, Florida beggarweed, sicklepod, common cocklebur, cutleaf eveningprimrose, and Florida pusley allowed little reproduction. Only Florida beggarweed was a consistently good host for the reniform nematode, though purple nutsedge and sicklepod were good hosts in one trial, and smallflower morningglory was a moderate host in both trials. Pigweed, prickly sida, Florida pusley, cutleaf eveningprimrose, yellow nutsedge, and common cocklebur were poor- to non-hosts for the reniform nematode. Most of the weeds tested would not perpetuate root-knot nematode or reniform nematode problems when non-host or nematode-resistant crops were grown.

Technical Abstract: Plant-parasitic nematodes which damage crops can also reproduce on weeds, thereby reducing the efficacy of nematode-suppressive crop rotations. However, the amount of reproduction by nematodes which damage cotton that occurs on weeds common in the major Southeastern crops is not known. This study documented the amount of Meloidogyne incognita and Rotylenchulus reniformis reproduction on common southeastern weeds: total reproduction and reproduction relative to cotton were measured. Final M. incognita egg counts on the plants tested ranged from 0% to 193% of the number on cotton in one trial and from 0% to 407% in the other trial, and final R. reniformis egg counts ranged from 0% to 105% in one trial and from 0% to 454% in the other trial. For M. incognita, only prickly sida was consistently a better host than cotton, though ivyleaf morningglory was a better host in one trial. Smallflower morningglory was a moderate host relative to cotton, whereas yellow and purple nutsedge, pigweed, Florida beggarweed, sicklepod, common cocklebur, cutleaf eveningprimrose, and Florida pusley were poor- to non-hosts. For R. reniformis, only Florida beggarweed was a consistently good host, though purple nutsedge and sicklepod were good hosts in one trial, and smallflower morningglory was a moderate host in both trials. Pigweed, prickly sida, Florida pusley, cutleaf eveningprimrose, yellow nutsedge, and common cocklebur were poor- to non-hosts for R. reniformis. Most of the weeds tested would not perpetuate M. incognita or R. reniformis problems when non-host or nematode-resistant crops were grown.