Document Type


Publication Date



With a nearly year-round growing season, tropical and subtropical regions are plagued with a myriad of agro-nomic challenges, including near-continuous weeds and invertebrate pests including plant-parasitic nematodes (PPNs). A poor understanding of the presence and geographical distributions of these pests complicate their man-agement, especially in organic farming systems. This work attempts to document the interaction of PPNs with the major weeds in the semi-arid region of south Texas. Five organically managed farms were surveyed for four weeds of regional agronomic importance including silverleaf nightshade (Solanum elaeagnifolium), common sunflower (Helianthus annuus), false ragweed (Parthenium hysterophorus), and London rocket (Sisymbrium irio). Soil and root samples were collected to determine the presence of economically important PPNs in the roots and rhizo-sphere of the selected weed species. Eight different nematode genera associated with the selected weed species, includingPratylenchus spp., Trichodorus spp., Criconemella spp., Helicotylenchus spp., Xiphinema spp., Dorylai-mus spp., Aphelencoides spp., and Tylenchus spp. were recorded. Four of the major economically important nema-tode genera (Pratylenchus spp, Trichodorus spp., Criconemella spp., Xiphinema spp.) were found in the rhizo-sphere of all four weeds. The two major PPN genera Helicotylenchus spp. and Pratylenchusspp., were largely asso-ciated with common sunflower, a major weed in the region. Our results indicate that these weed species can pre-sent additional challenges in agriculture, not only as direct competitors for resources to agronomic crops, but also as potential hosts for PPNs.


Uploaded with permission.

First Page


Last Page


Publication Title

Subtropical Agriculture and Environments



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.