HiMag (Reg. no. GP-79, PI 615587) tall fescue (Festuca
arundinacea Schreb.) was developed and released by the Missouri
Agricultural Experiment Station and the USDA-ARS
in 1997. HiMag has relatively high Mg and Ca concentrations
and low tetany ratio [K/(Ca + Mg)] expressed as moles of
charge.
Parental germplasm for the Co cycle of selection for HiMag
included 950 plants from 'Kenhy' (Buckner et al., 1977), 831
plants from 'Kentucky-31', and 688 plants from `Missouri-96'
(Asay et al., 1979). All plants were endophyte free [ Neotyphodium
coenophialum (Morgan-Jones and Gams) Glenn, Bacon,
and Hanlin comb. nov.]. Parental plants were transplanted to
the field near Columbia, MO, in the fall of 1983. The soil was
a Mexico silt loam (a fine, montmorillonitic, mesic Udollic
Ochraqualf) with a pH of 6.4. Selection was applied against
crown rust (caused by Puccinia coronata Corda. var. coronata),
leaving 1011 plants which were harvested in the fall of
1984 and analyzed for elemental concentrations of Mg, Ca,
K, and the tetany ratio. Sixty-five plants (11 from Kentucky-
31, 54 from Missouri-96, and 0 from Kenhy) were chosen to
generate the C1 cycle of selection. These 65 plants contained
5.0 to 7.0 g kg-1 Mg, 5.0 to 10.2 g kg' Ca, 20 to 33 g K,
and had K/(Ca + Mg) values of 0.61 to 0.99. These were
allowed to open-pollinate in the greenhouse during the winter
of 1985/86. Harvested seeds were germinated in the greenhouse
and seedlings were transplanted to the field in the fall
of 1986. During the fall of 1987 approximately 1000 plants
were analyzed from the CI cycle to determine elemental concentrations
of Mg, Ca, K, and the tetany ratio. Forty-six plants
chosen for the C2 contained 4.4 to 6.1 g kg -' Mg, 5.5 to 8.1 g
kg-' Ca, 17.2 to 30.9 g kg' K, and had tetany ratios of 1.06
to 2.13. These were allowed to open-pollinate in the greenhouse
in the winter of 1988-1989. Approximately 1000 seedlings
were transplanted to the field having areas of Creldon
silt loam (Mollic Fragiudalf) and Hobert silt loam (Umbric
Fragiaqualf) at the Southwest Research Center, located near
Mt. Vernon, MO, in the fall of 1989. In the summer of 1990,
seed was harvested from these spaced plants and planted into
an irrigated Portneuf silt loam soil (Durinodic Xeric Haplocalcid)
to establish a seed increase block at Kimberly, ID, in
April 1991. In 1992, seed from HiMag was harvested with the
following characteristics: 1635 kg ha-1, 400 seeds g-1, 2.5 g
1000 seeds-1, and 302 kg m-3
