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United States Department of Agriculture

Agricultural Research Service

Research Project: Nematode and Disease Management of Deciduous Fruits

Location: Fruit and Nut Research

Title: Field Performance of pecan rootstocks for resistance to Meloidogyne partityla in the southeastern United States

Author
item Nyczepir, Andrew

Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 4, 2012
Publication Date: June 1, 2013
Citation: Nyczepir, A.P. 2013. Field Performance of pecan rootstocks for resistance to Meloidogyne partityla in the southeastern United States. Nematropica. 43(1):63-67.

Interpretive Summary: The pecan root-knot nematode (PRKN) is associated with stressed trees exhibiting dead branches in the upper canopy and/or typical Mouse-ear associated foliar symptoms. Currently, there are no recommended resistant pecan rootstocks available for managing this nematode pathogen on pecan. Evaluating the only two commercially available open-pollinated pecan seedlings for nematode resistance is warranted. A long-term field microplot study was initiated to determine the host susceptibility of Elliott and Curtis pecan rootstocks for resistance to the PRKN. Results indicate that both commercial pecan rootstocks supported nematode reproduction and that the nematode was pathogenic such that tree growth was severely suppressed in its presence. These data provide useful insights into the need to further explore the development of IPM management strategies (i.e., resistance & biological control) for control of PRKN on pecan and their affect on orchard profitability.

Technical Abstract: Two open pollinated commercial pecan seedling rootstocks were evaluated for resistance to Meloidogyne partityla in field microplots. Rootstocks tested included seedlings derived from open pollinated seed of ‘Curtis’ and ‘Elliott’ parent trees. ‘Elliott’, a susceptible pecan seedling rootstock for M. partityla, also served as the identifiable control. Both commercial pecan rootstocks supported nematode reproduction as indicated by number of egg masses per plant, number of eggs per plant, and number of eggs per gram dry root and were not significantly different between rootstocks 30 months after inoculation. Differences in tree growth, as measured by trunk diameter and dry root weight, did not differ between ‘Elliott’ and ‘Curtis’ rootstocks, but growth suppression of both stocks was influenced in the presence of M. partityla. These results demonstrate that M. partityla is a potentially economically important pathogen to the pecan industry in the southeastern United States and that the search for an IPM management strategy (i.e., biological, chemical, etc.) for control of M. partityla on pecan is warranted.

Last Modified: 10/1/2014
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