Registration of ‘Kenhy’ and ‘Gibtuck’ Limpograss Hybrids

Abstract

‘Kenhy’ (Reg. No. CV‐283, PI 682663) and ‘Gibtuck’ (Reg. No. CV‐284, PI 682664) hybrid limpograss [Hemarthria altissima (Poir.) Stapf & C.E. Hubbard] cultivars were produced by the University of Florida Agronomy Department, a unit of the Florida Agricultural Experiment Station, and released in 2014. These two hybrids were selected from 51 hybrid seedlings produced by greenhouse hand crosses of ‘Floralta’ × ‘Bigalta’. Floralta is estimated to constitute >95% of the limpograss grown in Florida, raising concerns about genetic vulnerability. Bigalta, although less persistent than Floralta, has been shown to have slightly greater in vitro organic matter digestion. Evaluations of these hybrids were conducted at the Range Cattle Research and Education Center, Ona, FL, at two locations near Gainesville, FL, and at the North Florida Research and Education Center, Marianna, FL. Evaluations included greenhouse pot studies, small plot clipping experiments, two different mob stocking grazing experiments, and an experiment to evaluate herbage accumulation and nutritive value under stockpiling management. Kenhy and Gibtuck were selected for superior herbage accumulation, persistence under grazing defoliation, improved nutritive value compared with Floralta, and utility as stockpiled forage. Vegetative planting material was first distributed in summer 2014 to a group of growers selected by the Florida Cattlemen's Research Committee, and further public distribution will be coordinated by this committee.

In situ dry matter and crude protein disappearance dynamics in stockpiled limpograss

“…Limpograss is a C 4 forage species with potential to be used for deferred grazing in subtropical and tropical regions. Recent cultivar releases by the University of Florida (Quesenberry et al., 2018) gave producers improved alternatives for both biomass production and nutritive value. In this evaluation of their use as stockpiled forage, both Gibtuck and Kenhy outperformed industry standard Floralta in most parameters measured, especially related to digestibility and productivity.…”

“…‘Gibtuck’ and ‘Kenhy’ are recently released cultivars of limpograss with superior HA and persistence compared with industry standard ‘Floralta’ (Quesenberry et al., 2018; Wallau et al., 2016). They have shown excellent potential for use as stockpiled forage (Wallau et al., 2015), but greater understanding of the dynamics of ruminal dry matter (DM) and CP disappearance is needed in order to define supplementation strategies for cattle consuming stockpiled herbage of these new cultivars.…”

“…Hubb.] is a perennial warm-season (C 4 ) grass, which likely originated in east-central to southern Africa (Quesenberry et al, 2018). Limpograss has superior cool-season growth compared with other C 4 grasses (Quesenberry, Sollenberger, & Newman, 2004), is adapted to poorly drained soils, and has Abbreviations: CP, crude protein; DM, dry matter; DOM, digestible organic matter; HA, herbage accumulation; IVDOM, in vitro digestible organic matter.…”

“…Hubb.] is a perennial warm‐season (C 4 ) grass, which likely originated in east‐central to southern Africa (Quesenberry et al., 2018). Limpograss has superior cool‐season growth compared with other C 4 grasses (Quesenberry, Sollenberger, & Newman, 2004), is adapted to poorly drained soils, and has greater herbage digestibility at comparable maturity than most C 4 grasses (Lima, Sollenberger, Kunkle, Moore, & Hammond, 1999; Sollenberger et al., 1988; Sollenberger, Rusland, Jones, Albrecht, & Gieger, 1989).…”

Mob and rotational grazing influence pasture biomass, nutritive value, and species composition

“…Despite being adapted primarily for climates in the western United States, mob grazing has garnered interest among livestock producers in the eastern United States because of its purported pasture forage mass and soil quality benefits (Hafla et al, 2014). While some preliminary work has used mob grazing as a screening tool in forage breeding (Bittman & McCartney, 1994;Mislevy, Mott, & Martin, 1982;Quesenberry et al, 2018) and assessed individual farms that have implemented mob grazing (Hafla et al, 2014), there has been little work directly comparing the efficacy of rotational Because of the climate and pasture species differences across the United States, mob grazing may influence forage mass and nutritive value of eastern perennial-based pastures differently compared to the western United States. Grazing pressure has been demonstrated to differentially influence species prevalence in mixed pastures, and therefore different grazing management strategies are anticipated to influence species composition in temperate, cool-season perennial grass-legume pastures (Soder, Rook, Sanderson, & Goslee, 2007).…”