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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #145871
Title: WEEDS AS HOSTS FOR THE SOUTHERN ROOT-KNOT NEMATODE

Author
item Davis, Richard
item Webster, Theodore

Submitted to: Cotton Research and Extension Report
Publication Type: Experiment Station
Publication Acceptance Date: 3/1/2003
Publication Date: 4/1/2003
Citation: Davis, R.F., Webster, T.M. 2003. Weeds as hosts for the southern root-knot nematode. 2002 University of Georgia Cotton Research and Extension Report. p.318-319.

Interpretive Summary:

Technical Abstract: The southern root-knot nematode, Meloidogyne incognita, can reproduce on many different plants, including many weeds, but the amount of reproduction that occurs on weeds is not well documented. This study was conducted to document the relative host status of weeds common in Georgia. Seeds of cotton, peanut, Florida beggarweed, prickly sida, common cocklebur, smallflower morningglory, pigweed, sicklepod, cutleaf eveningprimrose, Florida pusley, purple nutsedge, yellow nutsedge, and ivyleaf morningglory were planted into pots for two greenhouse trails and inoculated with 8,000 M. incognita eggs/pot. Nematode eggs were extracted from all roots in a pot eight weeks after inoculation. Prickly sida was a very a good host for M. incognita and supported more nematode reproduction than cotton in both trials. It was the only weed in this study that consistently allowed more reproduction than cotton. Smallflower morningglory supported 54% of the reproduction on cotton in trial 1 and 71% in trial 2. Ivyleaf morningglory was more variable in its relative host status and supported 38% of the reproduction on cotton in trial 1 and 197% in trial 2. All other plants tested were relatively poor hosts for M. incognita with final egg counts ranging from 0 to 17% of the number on cotton in trial 1 and 0 to 28% in trial 2. For sicklepod, Florida beggarweed, cocklebur, eveningprimrose, Florida pusley, and peanut, the number of eggs recovered was less than the inoculum level of 8,000 eggs in both trials. The southern root-knot nematode, Meloidogyne incognita, can reproduce on many different plants, including many weeds, but the amount of reproduction that occurs on weeds is not well documented. This study was conducted to document the relative host status of weeds common in Georgia. Seeds of cotton, peanut, Florida beggarweed, prickly sida, cocklebur, small flower morning-glory, pigweed, sicklepod, primrose, Florida pusley, purple nutsedge, yellow nutsedge, and ivy-leaf morning-glory were planted into pots for two greenhouse trials and inoculated with 8,000 M. incognita eggs/pot. Nematode eggs were extracted from all roots in a pot eight weeks after inoculation. Prickly sida was a very good host for M. incognita and supported more nematode reproduction than cotton in both trials. It was the only weed in this study that consistently allowed more reproduction than cotton. Small-flower morning-glory supported 54% of the reproduction on cotton in trial 1 and 71% in trial 2. Ivy-leaf morning-glory was more variable in its relative host status and supported 38% of the reproduction on cotton in trial 1 and 197% in trial 2. All other plants tested were relatively poor hosts for M. incognita with final egg counts ranging from 0 to 17% of the number on cotton in trial 1 and 0 to 28% in trial 2. For sicklepod, Florida beggarweed, cocklebur, primrose, Florida pusley, and peanut, the number of eggs recovered was less than the inoculum level of 8,000 eggs in both trials.