Date of Award
Doctor of Philosophy (PhD)
Entomology, Soils and Plant Sciences
Bermudagrass mite (Aceria cynodoniensis Sayed) (Acari: Eriophyidae) infestation stunts bermudagrass growth, leading to thinned turf and lower aesthetic and recreational value. Cultural management practices may impact bermudagrass mite infestation and turfgrass recovery from mite damage. Scalping or mowing shorter may physically remove mites, while drought stress may increase grass susceptibility to mites. Fertilizer application may promote mite infestation by improving plant nutrition. I conducted greenhouse, nursery, and field experiments to evaluate the impact of nitrogen fertility, irrigation rate, mowing height, and scalping on turf health and bermudagrass mite infestation in terms of the densities of witch’s brooms (i.e., stunted and deformed terminals symptomatic of infestation) and mites. Also, we evaluated the impact of combining scalping and fertilizer and miticide application on mite infestation and turf recovery from infestation. I demonstrated that nitrogen fertility increased witch’s broom and mite densities and turf quality, coverage, and density. Irrigating at 60% of the evapotranspiration (ET) rate increased witch’s broom densities and reduced turf quality compared to irrigating at 100% or 140% of the ET rate. Irrigating at 140% of the ET rate reduced witch’s broom densities compared to irrigating at 100% of the ET rate. Mowing height had no consistent effect on witch’s broom or mite densities. Scalping reduced witch’s broom densities in potted bermudagrass turf but not on golf course turf. Clippings produced by mowing and scalping should be disposed of properly because, according to my laboratory studies, clippings serve as a major pathway for mite dispersal. Miticide consistently reduced mite infestation in all experiments. My research identified nitrogen fertilization and underwatering as factors that promote bermudagrass mite damage. Thus, limiting nitrogen fertilization to a level necessary to maintain turf health and quality and irrigating underwatered turf can complement current iii strategies to manage bermudagrass mite. Combining fertilizer with miticide application improves the management of mite infestation while enhancing turf recovery from mite damage. Effective miticides are unavailable on athletic fields, sod farms, and lawns. Therefore, modifying cultural practices is the only management strategy available.
Brown, Matthew, "Developing a Cultural Management Approach to Bermudagrass Mite (Acari: Eriophyidae) Infestation" (2023). All Dissertations. 3308.