Grazing Termination Date Influence on Annual Ryegrass Seed Production and Reseeding in the Southeastern USA

Abstract

Production costs could be reduced if annual ryegrass (Lolium multiflorum Lam.) could be managed for reseeding. Spring grazing termination dates (GTD) of 31 March, 14 April, 28 April, and 12 May were evaluated on seven cultivars for two growing seasons to study spring seed production and volunteer reseeding the following autumn in northeast Texas. There were year × GTD × cultivar interactions for spike density, seed yield, seed weight per spike, and volunteer seedling density and a year × GTD interaction for 1000‐seed weight. Moisture conditions were good during the 1994‐1995 growing season followed by a dry summer. Spike density was high (1256 ± 59 spikes m−2), seed yields were low (48.7 ± 3.2 g m−2), but seed weight was high with a 1000‐seed weight of 3.12 ± 0.03 mg. All cultivars exceeded the 500 seedlings m−2 target in 1995 when grazed through 28 April. In the 1996‐1997 growing season, May was very dry followed by high June rainfall. Spike density was lower but seed yields were higher than in 1995. However, 1000‐seed weight was only 1.37 mg. Only `Surrey' exceeded 500 seedlings m−2 through 28 April GTD, `TAM 90' through 14 April GTD, and `Rio', `Gulf', and `Jackson' at only one of the two early GTDs. The superior reseeding ability of Surrey is probably due to its selection for a high level of high temperature dormancy. In normal rainfall years in the southeastern USA, most cultivars of annual ryegrass can be grazed until late April and still produce satisfactory volunteer stands the following autumn.

A Novel Approach to Grass–Legume Management

“…Annual ryegrass is one of the most widely used cool season annual in pastures in the southeastern USA (Evers and Nelson, 2000) and its compatibility with clovers in mixtures, particularly white clover, is reported to be poor due to its aggressiveness under favorable conditions (Annicchiarico and Berardo, 1993). However, growing this grass as an adjacent monoculture in the same paddock has been suggested as a viable alternative, which has prompted several studies of their interactions between system components (Kennedy et al, 2007).…”

“…There are several important agronomic characteristics that account for the widespread use and popularity of this forage including high herbage yield, a long growing season, tolerance to a wide range of environmental conditions and grazing practices, rapid seedling establishment, weed suppression, excellent persistence under close grazing, compatibility with several forage legumes and excellent forage quality and palatability (Jung et al, 1996;Franca et al, 1998). Optimum growth of annual ryegrass is attained on soils of pH ≥ 5.7 with lower forage production on more acid soils (Evers and Nelson, 2000).…”

A Guide to Overseeding Warm-Season Perennial Grasses with Cool-Season Annuals

“…The first requirement for successful reseeding is to produce sufficient amount of seed in the spring. Stocking rates may have to be reduced or terminated by a certain date for satisfactory seed production (10). High temperature dormancy in annual ryegrass is the mechanism that prevents summer seed germination (15).…”

Establishment of Italian ryegrass (Lolium multiflorum Lam.) by self‐seeding as affected by cutting date and degree of herbage removal in spring in pastures of the southern Great Plains of the United States

“…, 2005) and it has a capacity for regeneration through self‐seeding (Prine et al. , 1982; Evers and Nelson, 2000). The ability of IRG to regenerate through seed can make it a persistent weed of winter wheat (Trusler et al.…”

“…Previous work has demonstrated that with early termination of grazing IRG can be grazed in spring without detriment to subsequent yield of seed (Young et al. , 1996) or to the production of seed sufficient for volunteer reseeding (Evers and Nelson, 2000). However, no estimate has been made of the reduction in herbage production of IRG arising from the early termination of grazing that is necessary to ensure an adequate supply of seed for self‐seeding.…”