Tall Fescue ‘Jesup (Max‐Q)’: Meloidogyne incognita Development in Roots and Nematotoxicity

• Published in: Agronomy journal 2013-05, Vol.105 (3), p.755-763
• Main Authors: Meyer, Susan L. F., Nyczepir, Andrew P., Rupprecht, Shannon M., Mitchell, Ashaki D., Martin, Phyllis A. W., Brush, Craig W., Chitwood, David J., Vinyard, Bryan T.
• Format: Article
• Language: English
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2012.0374

Tall fescue [Schedonorus arundinaceus (Schreb.) Dumont. cv. Jesup (Max‐Q)] was recently recommended as a preplant ground cover for managing plant–parasitic nematodes on peach trees [Prunus persica (L.) Batsch] in the southeastern United States. Jesup (Max‐Q) is associated with a strain of the endosymbiotic fungus Neotyphodium coenophialum that does not produce ergot alkaloids that cause fescue toxicosis. To optimize use of this tall fescue for lowering populations of the root‐knot nematode Meloidogyne incognita, greenhouse and laboratory studies were conducted on selected factors potentially contributing to suppression. Tall fescue–derived extracts and exudates were tested for nematotoxicity, and M. incognita life cycle development was compared between susceptible tomato (Solanum esculentum Mill.) and Jesup (Max‐Q) roots. The highest tested root and shoot extract concentrations inhibited M. incognita hatch up to 46% compared with controls, and were nematotoxic to the infective second‐stage juveniles (J2; up to 66% decrease in viability). Root exudates were nematotoxic to J2 (up to 27% mortality), and inhibited hatch up to 48%. Roots of susceptible tomato plants (controls) had approximately 3 to 7 times more infective J2 than tall fescue roots, 40 to 80 times more females and egg masses, >1800 times more eggs/plant, and 10 to 83 times more galls/plant. The nature of Jesup (Max‐Q) suppression of M. incognita included low J2 penetration rate and failure of infective J2 to complete their life cycle in this cultivar. Compounds derived from Jesup (Max‐Q) tall fescue decreased nematode viability, also contributing to M. incognita suppression by this plant.