Abstract

Bermudagrass (Cynodon spp.) turf in subtropical Florida normally requires higher levels of N than other grasses and frequently requires pesticide applications.  Three sequential 2-year cycles of clonal selection were performed in replicated field plots to recognize bermudagrass germplasm adapted to suboptimal fertilization and natural pest infestation.  Low fertility, 19 to 25 g N m^-2, was applied yearly, including the establishment phase.  No nematicides, fungicides, or insecticides were applied.  Severely damaging mole cricket (Scapteriscus sp.) populations were left uncontrolled.  Among 95 clones, 4 experimentals (FB-109, PI-291586, T-72-54, and FL-2400) survived repeated cycles with relatively high turfgrass coverage and quality.  Among cultivars, only 'Tifgreen-II' and 'Ormond' performed well.  African introductions and artificially-induced mutants of hybrid cultivars were the best sources of adapted germplasm.  Although the mechanism of this adaptation is unknown, field tests were an effective presreening method for clonal selection.