Busey, P. 1986. Bermudagrass germplasm adaptation to natural pest infestation and suboptimal nitrogen fertilization. J. Am. Soc. Hort. Sci. 111:630-634.
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.