Annual Ryegrass (Lolium multiflorum)

Plant Characteristics: Annual cool-season bunchgrass, soft clasping auricles are present, and plant base is often purplish. Leaves are dark and shinny with smooth edges and rolled in the bud (in contrast to those of perennial ryegrass, which are folded). They are prominently ridged on the upper surface. Lower surfaces are smooth, glossy, and hairless, with a prominent midrib. Leaf margins are slightly rough to the touch. The leaf sheath is split and overlapping, with no hairs. The root system of annual ryegrass is highly branched and dense, with many fibrous, adventitious roots. Annual ryegrass has no rhizomes or stolons. The inflorescence of annual ryegrass is a solitary spike with alternately arranged spikelets attached edgewise directly to the central axis.

Establishment: Annual ryegrass is a fast-growing, competitive winter annual cool-season grass grown nearly anywhere there is adequate available soil moisture. Tolerates wet, poorly drained soils, but not extensive periods of flooding. It could be seeded alone, with small grains, legumes (clover), or overseeded in warm-season pastures (bermuda or bahiagrass). Annual ryegrass is usually planted from September to early October at rate of 20 to 30 lb/c in pure stand or 10 to 15 lb/ac in a mixture (small grains or overseeding bermudagrass or bahiagrass). overseeding of warm-season grassed should be done in November and make sure that enough forage has been removed to allow a good soil-seed contact. Armyworms and rust could be a problem. Seeding depth should be between 1/4 and 1/2 inch.

Fertilization: Tolerant to moderate acidity. Annual ryegrass will grow over a wide range of soil pH levels but grows best at a pH level of 6.0 to 7.0. Annual ryegrass responds to high soil nutrient levels. Fertilization should be based on a soil test recommendations. Phosphorus and potassium should be at least in the medium range for optimum yields. Up to 60 lbs phosphate (P₂O₅) per acre should be applied if soil-test P levels are low (<60 lbs/acre). No additional P₂O₅ is necessary if soil-test P is greater than 100 lbs/ac; intermediate application rates can be used if soil tests indicate P levels to be between 60 and 100 lbs/ac. Typically, applications of potash (K₂O) that range between 30 and 60 lbs/ac are recommended if soil test potassium (K) levels fall below 200 lbs/acre. Depending on planting date and expected growth during fall and early winter, the appropriate nitrogen rate at establishment is normally 40 to 60 lbs N/ac, 50% of the recommended K₂O and all of the P₂0₅ fertilizer. After the first grazing or hay harvest, apply 50 lbs N/ac and the remaining K₂O. Top-dressing with 50 lbs N/ac after each additional grazing or hay harvest, except at the end of the season, is recommended for the productivity of the ryegrass.

Grazing/Hay Management: It is very useful as an interim crop between summer annual forage crops as row crops, between permanent pasture seedings, or for overseeding of warm-season forages species. Annual ryegrass is used mainly for pastures. In the Gulf Coast regions, reason productivity can be expected from November to May. In the northern part of the state, productivity is seen from mid-February to May. Typical yields of annual ryegrass are 2 to 6 tons/ac. Annual 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.

Forage Quality: Annual ryegrass is considered to be one of the highest quality winter forages utilized in the in Mississippi. It usually contains 14 to 18% CP, 60 to 70% TDN, and dry matter digestibiltiy usually greater than 65%.

Annual ryegrass toxicosis could be a problem. It is a disease of livestock caused by a group of highly toxic compounds called corynetoxins. They are produced only when annual ryegrass is infected with a specific nematode (Anguina agrostis), and only when that nematode is infected by a bacteria. Control of annual ryegrass toxicosis involves preventing nematode infection of the grass. Crop rotation, field burning, clipping immature seed heads, and fallowing are methods of reducing nematodes.

Varieties/Cultivars: Marshall, TAM 90, Passarel Plus, Bulldog Grazer, Brigadier, Big Boss, Jackson, Stampede, Ribeye

Maturity: Crown rust resistance (0-3 is highly resistant, 3-5 is resistant, 5-7 susceptible and above 7, highly susceptible ), and cold tolerance of several ryegrass cultivars.