ISHS Acta Horticulturae 783: II International Conference on Turfgrass Science and Management for Sports Fields
ZOYSIAGRASS (ZOYSIA SPP.) RESISTANCE TO FALL ARMYWORM (SPODOPTERA FRUGIPERDA): POLYPHENOLS AND FLAVONOIDS ¿ COMPONENTS OF RESISTANCE |
| Authors: | T.C. Hale, R.H. White, J.A. Reinert, M.E. Snook |
| Keywords: | host plant resistance, Zoysia japonica, Zoysia matrella, Spodoptera frugiperda, turfgrass, eriophyid mites, pest management |
| Abstract:
Leaf tissue collected from six zoysiagrass (Zoysia spp.) cultivars was analyzed for polyphenols and flavonoids by high performance liquid chromatography (HPLC). The experiment investigated the effects of sampling date and N fertilization rate on green leaf chemistry of zoysiagrass and their relationship to fall armyworm (FAW) [Spodoptera frugiperda (J. E. Smith)] resistance. Six zoysiagrasses cultivars {Crowne= (Z. japonica Steud.), Palisades= (Z. japonica Steud.), El Toro= (Z. japonica Steud.), Meyer= (Z. japonica Steud.), Cavalier= [Z. matrella (L.) Merr.], and 'Emerald' (Z. japonica Stued. × Z. tenuifolia Willd. ex Trin.)} were planted in a randomized split-plot design with 4 replicates using cultivars as the main plot and 12.2 and 48.9 kg of N ha-1 month-1 [(NH4)2SO4] as the split plots. Flavonoid concentration decreased as the amount of applied N increased. Flavonoid concentration was greatest in June and steadily declined throughout July and August. Two unidentified flavonoids (luteolin-glycosides) were consistently associated with FAW mortality when analyzed by stepwise regression techniques. Unidentified luteolin 3 had an inverse relationship with mortality, while unidentified luteolin 9 was positively correlated with mortality. Additional research is needed to determine if the concentration of luteolins found in resistant zoysiagrasses are sufficient to cause biocidal activity in FAW. | |
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