Floral Induction and Forage Yield and Quality of Sparse‐Flowering Orchardgrass Synthetics¹

Abstract

The purpose of this research was to ascertain the genetic control of reproductive tiller production in orchardgrass (Dactylis glomerata L.) and to determine whether sparse panicle production affects.forage yield and quality. We postulated that sparse‐flowering synthetic would retain forage quality longer than normal cultivars as reproductive tillers mature in late spring and early summer. In the greenhouse, up to 12 weeks of cool, short days were required before some orchardgrass plants would flower under long‐day conditions. The response of progeny from three crosses to floral induction treatments suggested that a complex interaction of genetic and environmental factors controls the onset and rate of reproductive tiller production. Reciprocal differences were not observed. Syn 2 generation of synthetics, that produced relatively few flowering tillers when grown in the northeastern USA, flowered and produced satisfactory seed yields at Prosser, Wash.In the field under a hay management cutting system, the most sparse‐flowering synthetic had slightly lower first harvest forage yield in June. than the check cultivars, possibly because dry matter was produced rapidly by the flowering culms of the cultivars. The absence of significant differences among entries for in vitro dry matter disappearance or lignin concentration suggests that the synthetics and cultivars were similar in forage quality. Thus, the experimental strains exhibited no apparent improvement in forage production or quality.

Flowering traits in tetraploid Brachiaria ruziziensis breeding

“…These results differ from those obtained by Casler et al (2014), in which sparse flowering cultivars presented 9% more crude protein and 3% less NDF in orchardgrass, but they corroborate with previous studies in which there was no evidence of the effect of flowering on the forage quality in the same species (Berg et al 1981). …”

Sparse‐Flowering Orchardgrass is Stable Across Temperate North America

“…The feasibility of deploying sparse‐flowering orchardgrass cultivars has received limited investigation (Berg et al, 1981; Casler et al, 2010). The smooth bromegrass cultivar Rebound received registration in Canada in the 1980s based on its high digestibility, which was related to its sparse‐flowering trait (Bittman et al, 1989).…”

“…The smooth bromegrass cultivar Rebound received registration in Canada in the 1980s based on its high digestibility, which was related to its sparse‐flowering trait (Bittman et al, 1989). Berg et al (1981) compared sparse‐ and normal‐flowering populations under mild and severe winter conditions while Casler et al (2010) evaluated progeny of selected nonflowering plants under mild winter conditions. Both studies demonstrated a modest degree of seed production, not equal to the best cultivars but probably sufficient for a successful value‐added cultivar.…”

“…Because orchardgrass flowering is induced by prolonged exposure to short days of autumn, longer winters or earlier onset of cold temperatures will suppress flowering (Heide, 1987). Plants originating or undergoing natural selection under prolonged cold temperatures have longer winter dormancy periods than those from milder climates, restricting their physiological activity during short-day induction periods (Berg et al, 1981). Consequently, sparse-flowering and nonflowering plants can be more easily identified under more severe or prolonged winter conditions (Casler et al, 2004(Casler et al, , 2010.…”

Feasibility of Seed Production from Nonflowering Orchardgrass

“…Although hundreds of cultivars have been developed within this species, seed markets are generally dominated by early fl owering cultivars, largely because they tend to have the greatest seed production, reducing the cost of seed to forage producers (Casler et al, 1997(Casler et al, , 2000. Hovin et al (1966) developed two sparse-fl owering orchardgrass populations that had normal panicle and seed production in eastern Washington, but severely reduced panicle production in Pennsylvania and Vermont (Berg et al, 1981). Although the concept of using nonfl owering or sparse-fl owering cultivars to avoid this problem has been known for many years, there has been little progress toward developing cultivars that possess this trait in a pasture setting, but also are capable of economically viable seed production.…”