Annual ryegrass is widely grown in the southern US and has become an important component in winter forage-livestock systems. Annually, more than one million hectares of annual ryegrass are grown in the Southeast. Annual ryegrass has become a highly valued and productive cool season forage. This publication will discuss the applications of annual ryegrass in South Florida forage-livestock systems.

Ryegrass has been adapted to many soil types and a wide range of soil pH. Optimum growth occurs at pH 5.6 or higher (Target pH = 6.0).

There are many cultivars of annual ryegrass to choose from diploid to tetraploid or early maturing to late maturing. The key is to select a cultivar that best matches your operation and objectives, and based on reliable, unbiased information.

Planting Annual Ryegrass

Soil testing prior to the planting season is important to determine soil fertility and recommended fertilizer application rates. It is recommended that soil be tested no later than three months before planting.

In South Florida, November and December are generally optimal months to seed ryegrass. It is recommended, in South Florida, to plant from November 1-December 15.

Annual ryegrass forage production peaks when daytime air temperatures are between 60 and 75 degrees. Dormancy occurs when temperatures rise above 90 degrees and below 50 degrees. In the Polk, Hardee, Highlands and DeSoto region, that period translates to a growing season from about mid-October to early-April.

Ryegrass can be planted on a prepared seedbed or overseeded into dormant permanent pasture. It can be seeded with a broadcast application then pressed in with a cultipacker, or using a drill. Seed should be planted to a depth of no more than ½ inch. Cultipacking or dragging the soil following broadcast applications is recommended to establish good seed-to-soil contact.

Recommended seeding rates:

If planting over dormant perennial pasture, plant later and mow or graze the existing forage very short and later in the season to decrease competition between warm season grasses and annual grass seedlings. Producers must consider that later planting will generally result in later ryegrass production and total tonnage will be reduced.

Planting ryegrass in a mixture with other cool season forages may extend the winter grazing period because ryegrass is competitive with small grains. Although small grains are faster growing and provide earlier grazing than ryegrass alone, the small grains decline in late winter when ryegrass production peaks. Thus extending the winter grazing period. However, in South Florida’s warmer climate this difference may not be significant.

Establishment of ryegrass is highly dependent on “effective” precipitation – the right amount of water at the right time. It is crucial that ryegrass plantings receive adequate water. This is challenging for non-irrigated pastureland. Producers should only consider planting annual ryegrass in years where above average rainfall is expected.

Managing Annual Ryegrass Stands

Forage yield is enhanced with additional N applications and irrigation. Fertilization recommendations should be based on soil test results. General recommendations at planting include 30 lbs N/A, 50% of the recommended K and all of the recommended P fertilizer. After the first grazing or harvest, apply 50 lbs N/A and the remaining K. Top-dressing with 50 lbs N/A after each additional grazing or harvest, except at the end of the season, is recommended for the productivity of the ryegrass.

Ryegrass can be grazed when plants reach an approximate height of 6-8 inches. Animals can graze the forage as low as 2-4 inches, which allows sufficient leaf area remaining for regrowth.

While ryegrass is extremely tolerant of close grazing by livestock, rotational grazing gives the grazed pasture time to regrow and allows for more efficient utilization of the forage.

In years of excess forage production, ryegrass may be cut for hay, haylage or silage.

Forage Yield and Quality

Typical yields from non-irrigated annual ryegrass are 2-4 ton of dry matter/A.

Annual ryegrass is considered to be one of the highest quality winter forages utilized in the southeastern US. Dry matter digestibility is generally greater than 65%, and crude protein content exceeds the requirements for most classes of livestock animal gains. Because ryegrass is highly palatable, livestock may overconsume. Avoid turning hungry animals directly onto lush (especially first growth) ryegrass pastures. Use hay as a filler prior to grazing until animals have adjusted to the new diet. Also, provide hay while animals are grazing ryegrass.

Grass tetany, sometimes called grass staggers or hypomagesemia, can be a problem in Florida with cattle grazing ryegrass pastures if they overconsume. Following the management guidelines above will help in preventing this condition. For more information, see publication SS-AGR-64, Grass Tetany in Cattle, which can be found at https://edis.ifas.ufl.edu/ds137.

Pest Management

Crown rust (Puccinia coronate) has long been the most common disease affecting ryegrass production. Selection through breeding has improved ryegrass resistance. Early infection greatly reduces forage production. The disease is easily recognized by the bright orange-to-red pustules that occur scattered on the leaf blades, resulting in leaf chlorosis and, in some severe cases, dwarfed plants. Late infection generally does not greatly reduce forage production. Most new varieties have good to excellent crown rust resistance.

Gray Leaf Spot, caused by Pyricularia sp., may occur on early planted ryegrass pastures. Plants that show symptoms usually have been stressed from drought and warm temperatures early in the season. The disease dissipates with cooler weather and usually does not present a risk to forage plantings.

Regardless of the cultivar, cottony blight (Pythium aphanidermatum) disease can attack ryegrass seedlings causing severe stand losses when soil temperature is 70˚ or higher. The disease activity decreases as temperatures decline, thus early plantings may be vulnerable.

Information on weed control in annual ryegrass may be found in the fact sheet SS-AGR-08 Weed Control in Pastures and Rangelands. This fact sheet is available at http://edis.ifas.ufl.edu/wg006.

Conclusion

Annual ryegrass is a high quality winter forage that can work in South Florida forage-livestock operations. Producers should consider and weigh the options of cultivars, planting time, planting resources, and water availability when deciding whether or not annual ryegrass is a good fit for the upcoming winter feeding season.

References

Blount, A. R., and G. M. Prine. “Annual Ryegrass.” EDIS, UF/IFAS, 29 Apr. 2016, edis.ifas.ufl.edu/ag104.

“FAWN – Florida Automated Weather Network.” FAWN – Florida Automated Weather Network, UF/IFAS, fawn.ifas.ufl.edu/.

Newman, Y. C., et al. “Grass Tetany in Cattle.” EDIS, UF/IFAS, 6 Jan. 2017, edis.ifas.ufl.edu/ds137.

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