Resistance of Zoysiagrass to Fall Armyworm.
(C05-hale753092-poster)
Authors:
T.C. Hale* - Clemson Univ.
R.H. White - Texas A&M Univ.
J.A. Reinert - Texas A&M Univ.
Abstract:
The effects of sampling date and applied nitrogen (N) on concentration of flavonoids, hemicellulose, lignin, cellulose, silica, percent cell wall and leaf tensile strength in six zoysiagrass cultivars were determined at Texas A&M University Turfgrass Research Lab. ‘Cavalier’, ‘Emerald’, ‘Crowne’,
‘Palisades’, ‘El Toro’ and ‘Meyer’ zoysiagrass cultivars were grown in a randomized split-plot design with N applied as ammonium sulfate at 12.2 and 48.9 kg of N ha -1 month -1 during the growing season and treatments replicated 4 times. Samples were taken monthly from June through August, and analyzed for flavonoid concentration using HPLC techniques. Percent cell wall, hemicellulose, lignin, cellulose and silica were determined by a standard forage analysis procedure. Fall armyworm (FAW) mortality was calculated from feeding trials conducted by previous researchers and correlated with chemical data in this study. Sampling date and applied N affected flavonoid concentration in fresh leaf tissue of
zoysiagrasses. Flavonoid concentration was greatest in June and declined in July and August. Flavonoid concentration in fresh leaf tissue decreased as applied N increased. Two flavonoids identified as luteolin glycosides, lignin, tensile strength and hemicellulose were correlated with FAW mortality when analyzed by stepwise regression techniques.
Speaker Information: Trent Hale, Clemson Univ., 2200 Pocket Road, Florence, SC 29506-9706; Phone:
843.662.3526 x 206; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 725)
Keywords: zoysiagrass; insect resistance; flavonoids; high performance liquid chromatography
