Perennial Ryegrass

Perennial Ryegrass

 

Growing Period Type Annual or Perennial Drought Tolerance Shade Tolerance Salinity Tolerance
Cool Season Grass Perennial Low Intolerant High
"Lolium perenne" by Matt Lavin is licensed with CC BY-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/2.0/
"Lolium perenne" by Matt Lavin is licensed with CC BY-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/2.0/

Common Name

Perennial ryegrass or English ryegrass (Munz, 1973).

Scientific Name

Lolium perenne L., Poaceae (Wiles et al., 1989).

Cultivar

Erect and prostrate forms of Kangaroo Valley perennial ryegrass are available (Shah et al., 1990).

Late mowing led to a greater yield (dry matter) by the early maturing variety 'Gremie', whereas frequent mowing initiated early led to a greater yield by the late-heading variety, 'Vigor' (Taube, 1990).

Seed Description

Kangaroo Valley perennial ryegrass seed weight ranged from 1.74 to 2.36 mg per seed (Shah et al., 1990).

Seedling Description

Perennial ryegrass has slower seedling establishment and lower seedling vigor than does annual ryegrass (Miller, 1984).

Mature Plant Description

Both annual and perennial ryegrasses are bunch grasses (Miller, 1984).

Erect and prostrate forms of Kangaroo Valley perennial ryegrass are available (Shah et al., 1990).

Temperature

Lolium multiflorum and Lolium perenne are not so winter hardy as timothy or orchardgrass (Miller, 1984).

Geographic Range

Lolium multiflorum and Lolium perenne are tolerant of a wide range of soils and climates, do better than small grains on wet soils, but perform best on well-drained soils (Miller, 1984).

Lolium multiflorum and Lolium perenne will tolerate temporary flooding (Miller, 1984).

Lolium multiflorum and Lolium perenne will grow on sandy soils if they are well fertilized but do better on heavier clay or silty soils with adequate drainage (Miller, 1984).

Water

Lolium multiflorum and Lolium perenne are tolerant of a wide range of soils and climates, do better than small grains on wet soils, but perform best on well-drained soils (Miller, 1984).

Lolium multiflorum and Lolium perenne will tolerate temporary flooding (Miller, 1984).

Lolium multiflorum and Lolium perenne will grow on sandy soils if they are well fertilized, but do better on heavier clay or silty soils with adequate drainage (Miller, 1984).

When soil moisture is low in the summer, perennial ryegrass goes dormant (Miller, 1984).

Soil pH

Will not tolerate a high pH of 8.0 to 8.5. It causes root burning. (Fred Thomas, pers. comm.)

Soil Type

Lolium multiflorum and Lolium perenne are tolerant of a wide range of soils and climates, do better than small grains on wet soils, but perform best on well-drained soils (Miller, 1984).

Lolium multiflorum and Lolium perenne will tolerate temporary flooding (Miller, 1984).

Lolium multiflorum and Lolium perenne will grow on sandy soils if they are well fertilized but do better on heavier clay or silty soils with adequate drainage (Miller, 1984).

Life Cycle

In most of California, perennial ryegrass behaves as a cool-season perennial (Bugg, pers. comm.). When soil moisture is low in the summer, perennial ryegrass goes dormant (Miller, 1984).

Perennial ryegrass is self-incompatible (an obligate outcrosser); inbreeding depression can be severe (Wilkins, 1991).

Perennial ryegrass stands can be maintained for about 3-4 years (Miller, 1984).

Seeding Rate

Both annual and perennial ryegrasses should be sown at 20-28 kg/ha (18-25 lb/a) for pure stands, and 11-17 kg/ha (10-15 lb/a) if sown along with a legume or a small grain (Miller, 1984).

Seeding Depth

Both annual and perennial ryegrasses should be seeded at a depth of 1.25 cm (Miller, 1984).

Seeding Method

Both annual and perennial ryegrasses should be sown at 20-28 kg/ha (18-25 lb/a) for pure stands, and 11-17 kg/ha (10-15 lb/a) if sown along with a legume or a small grain (Miller, 1984).

Both annual and perennial ryegrasses can be seeded into bermuda grass sod (Miller, 1984).

Seeding Dates

In the warm California valleys it should be seeded from September to April. In the Intermountain area it should be seeded in the spring. (Fred Thomas, pers. comm.)

Inoculation

Perennial ryegrass is a grass, and is usually regarded as requiring no inoculation prior to sowing (R.L. Bugg, pers. comm.).

Seed Availability

Seed is adundant for both annual and perennial ryegrasses (Miller, 1984). Southern Seedsmen's Association 1990-91 Directory and Buyers' Guide lists 36 suppliers of seed.

Days to Flowering

According to Munz (1973), perennial ryegrass flowers from May to September in California. For the Kangaroo Valley cultivar complex from Australia, days to flowering (anthesis) following seedling emergence ranged from 139 (population 130b) to 156 (population 77b) (Shah et al., 1990).

Seed Production

Perennial ryegrass is self-incompatible (an obligate outcrosser); inbreeding depression can be severe (Wilkins, 1991).

Growth Habit

Erect and prostrate forms of Kangaroo Valley perennial ryegrass are available (Shah et al., 1990).

Mediterranean varieties of ryegrass show summer dormancy (Wilkins, 1991).

Maximum Height

Perennial ryegrass attains a height of about 90 cm (36 in.) according to Miller (1984a), and 30-60 cm according to Munz (1973).

Establishment

Perennial ryegrass has slower seedling establishment and lower seedling vigor than does annual ryegrass (Miller, 1984).

Maintenance

Perennial ryegrass stands can be maintained for about 3-4 years (Miller, 1984). Perennial ryegrass responds positively to close but infrequent mowings (every 30 to 31 days); this sort of mowing regime may help maintain perennial ryegrass in the presence of taller-statured grasses, such as orchardgrass (Kanyama-Phiri et al., 1990).

In strawberry clover - white clover - perennial ryegrass - orchardgrass mixtures, close mowing alternating with 30-31 day regrowth periods apparently favors the two clovers and the perennial ryegrass (Kanyama-Phiri et al., 1990).

Mowing

Both annual and perennial ryegrasses should be cut no closer to the ground than about 7.5 cm (3 in.) (Miller, 1984a).

Perennial ryegrass responds positively to close but infrequent mowings (every 30 to 31 days). This sort of mowing regime may help maintain perennial ryegrass in the presence of taller statured grasses, such as orchardgrass (Kanyama-Phiri, Raguse, and Taggard, 1990). In strawberry clover - white clover - perennial ryegrass - orchardgrass mixtures, close mowing alternating with 30-31 day regrowth periods apparently favors the two clovers and the perennial ryegrass (Kanyama-Phiri et al., 1990).

Studies in Wales indicated that there were varietal differences in yielding of cultivars of Lolium perenne, with Ba 10761 outyielding Talbot by 15% under frequent harvesting (1-2 week intervals) and 5% under infrequent harvesting (4-5 week intervals). Annual dry matter yields for the four varieties tested were for the two years of the study (across both harvesting regimes, in metric tonnes per hectare [Mg/ha]): Ba 10761: 8.29 and 8.46, Talbot: 7.77 and 7.75, Tove: 8.36 and 7.76, and S.321: 7.90 and 6.97. Where harvesting was infrequent, dry matter yields were higher, as indicated: Ba 10761: 11.66 and 11.50, Talbot: 11.34 and 10.73, Tove: 12.27 and 10.60, and S.321: 11.61 and 9.48. There were significant interactions between variety and harvesting frequencies. That is, some varieties performed best under frequent harvesting, others with infrequent harvests. However, the author suggested that it should be possible to anticipate differences in dry-matter yield under a system involving 6 cuts per year (Wilkins, 1989).

Perennial ryegrass sod led to reduced foliar concentration of N, S, Ca, B, and Mn in 'Chardonnay' wine grape vines. Mowing the grass did not alleviate the competition (Tan and Crabtree, 1990).

Late mowing led to a greater yield (dry matter) by the early maturing variety, 'Gremie', whereas frequent mowing initiated early led to a greater yield by the late-heading variety, 'Vigor' (Taube, 1990).

Uses

Perennial ryegrass is the most important of the perennial grasses worldwide (Wilkins, 1991).

Strips of perennial ryegrass can facilitate harvest of interplanted pak choi during cool, wet weather. The perennial ryegrass can help reduce soil compaction caused by traffic through muddy fields. The living mulch might also reduce weed infestations, soil erosion, and fertilizer needs, and enhance soil organic matter, water infiltration, and retention of nutrients and moisture. A possible problem is interference by the perennial ryegrass with the economic crop (Wiles et al., 1989).

A three-year field study of strawberry (Frageria X ananassa Duchesne, Rosaceae, cv 'Sparkle' and 'Honeoye') showed that living mulches of wheat (Triticum aestivum L.), Kentucky bluegrass (Poa pratensis L.), or perennial ryegrass (Lolium perenne L.) provided protection from winter storms, and thereby improved fruit yield and quality. When snow covered the strawberry plants, living mulches did not enhance yield or quality. Plots with living mulches showed less soil compaction. When wind damaged strawberry blossoms, yields were better in plots with living mulches. When no such damage occurred, yields did not differ. Living mulches effectively suppressed weeds. Perennial ryegrass, which spreads by tillering but did not invade the strawberry rows, and which grows tall enough to provide wind protection, appeared the best living mulch tested (Newenhouse and Dana, 1989).

Increased efficiency of N-uptake could have important ramifications in avoiding excess leaching of nitrates. Studies in Wales indicate that the newest variety of perennial ryegrass, Ba 10761 gave a 20% higher yield of nitrogen than did the oldest, S.321. Nitrogen was applied at three rates: 0.6, 0.4, and 0.2 t/ha. Overall mean proportions of nitrogen recovered over nitrogen applied were as follows for the four varieties tested Ba 10761: 0.62, Talbot: 0.57, Tove: 0.56, and S.321: 0.51 (Wilkins and Lovatt, 1989).

Mixtures

When seeded along with legumes or some other grasses, annual and perennial ryegrasses contribute to better control of weeds (Miller, 1984).

Both annual and perennial ryegrasses can be sown along with small grains, such as cereal rye and to some extent oat. Oat does not complement ryegrasses as well because forage is produced at the same time (Editor's note: cereal rye produces earlier) (Miller, 1984).

Both annual and perennial ryegrasses should be sown at 20-28 kg/ha (18-25 lb/a) for pure stands, and 11-17 kg/ha (10-15 lb/a) if sown along with a legume or a small grain (Miller, 1984).

Both annual and perennial ryegrasses can be seeded into bermuda grass sod (Miller, 1984).

Mixtures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) yield less than heavily fertilized monocultures of the former. Addition of small amounts of nitrogen in the spring lead to reduction of the proportions of clover in the stand. The present study indicates that the relative growth rate of clover is as great as that of the grass when nitrogen is added and greater when nitrogen is not added. There was no evidence that fertilized grass overtopped clover. Clover showed a smaller ratio of leaf area to total above-ground dry weight, but had a higher proportion of its lamina in the upper, well-lit strata (Woledge, 1988).

Perennial ryegrass responds positively to close but infrequent mowings (every 30 to 31 days). This sort of mowing regime may help maintain perennial ryegrass in the presence of taller-statured grasses, such as orchardgrass (Kanyama-Phiri et al., 1990). In strawberry clover - white clover - perennial ryegrass - orchardgrass mixtures, close mowing alternating with 30-31 day regrowth periods apparently favors the two clovers and the perennial ryegrass (Kanyama-Phiri et al., 1990).

Trifolium repens in the same 1-ha old field will diverge genetically through time depending on the grass species with which it is associated. Reciprocal transplant experiments have demonstrated differential success of T. repens from areas dominated by the grasses Lolium perenne or Agrostis capillaris to areas dominated by the original grass or other perennial grasses. The results suggest that, even within a field, white clover clones are genetically adapted to perform better amid stands of particular grasses (Turkington, 1989).

Studies by McNeill and Wood (1990) using an environmental chamber with an atmosphere enriched by 15N indicated that white clover did not rapidly transfer nitrogen to associated ryegrass. The plants were mycorrhizal.

Biomass

Studies in Wales by Wilkins (1989) indicated that there were varietal differences in yielding of cultivars of Lolium perenne, with Ba 10761 outyielding Talbot by 15% under frequent harvesting (1-2 week intervals) and 5% under infrequent harvesting (4-5 week intervals). Annual dry matter yields for the four varieties tested were for the two years of the study (across both harvesting regimes, in metric tonnes per hectare): Ba 10761: 8.29 and 8.46, Talbot: 7.77 and 7.75, Tove: 8.36 and 7.76, and S.321: 7.90 and 6.97. Where harvesting was infrequent, dry matter yields were higher, as indicated: Ba 10761: 11.66 and 11.50, Talbot: 11.34 and 10.73, Tove: 12.27 and 10.60, and S.321: 11.61 and 9.48. There were significant interactions between variety and harvesting frequencies. That is, some varieties performed best under frequent harvesting, others with infrequent harvests. However, the author suggests that it should be possible to anticipate differences in dry-matter yield under a system involving 6 cuts per year.

Late mowing led to a greater yield (dry matter) by the early maturing variety, 'Gremie', whereas frequent mowing initiated early led to a greater yield by the late-heading variety, 'Vigor' (Taube, 1990).

Eight- and fifteen-year-old swards of perennial ryegrass contained 3,000 kg/ha of above-ground biomass (stubble), an average 500 kg/ha of biomass in litter, an average of 11,500 kg/ha of root biomass, and an average 8,800 kg/ha of soil macro-organic matter (Whitehead et al., 1990).

N Contribution

Eight- and fifteen-year-old swards of perennial ryegrass contained on average 68 kg/ha of above-ground nitrogen (stubble), 12 kg/ha of nitrogen in litter, 249 kg/ha nitrogen in root biomass, and 240 kg/ha of nitrogen in soil macro-organic matter (Whitehead et al., 1990).

Increased efficiency of N-uptake could have important ramifications in avoiding excess leaching of nitrates. Studies by Wilkins and Lovatt (1989) in Wales indicate that the newest variety of perennial ryegrass, Ba 10761 gave a 20% higher yield of nitrogen than did the oldest, S.321. Nitrogen was applied at three rates: 0.6, 0.4, and 0.2 t/ha. Overall mean proportions of nitrogen recovered over nitrogen applied were as follows for the four varieties tested Ba 10761: 0.62, Talbot: 0.57, Tove: 0.56, and S.321: 0.51.

Theiss (1990) reported that after high initial rates of N fertilization, perennial ryegrass does not appear as efficient at N uptake as are annual ryegrass and cocksfoot (Dactylis glomerata). However, the release of nitrogen from perennial ryegrass swards apparently takes place later in the autumn than for the other two grasses. Thick stands of grasses (perennial ryegrass, annual ryegrass and cocksfoot [Dactylis glomerata]) are more effective at N uptake than are open stands. Drought stress reduced N uptake by annual ryegrass more than by perennial ryegrass or cocksfoot.

In Germany, winter crops of rape, barley, and Welsh ryegrass respectively accumulated in their above-ground structures 52.1, 36.2, and 22.9 kg N/ha following bell bean (cv 'Alfred') (Raderschall and Gebhardt, 1990).

McNeill and Wood (1990) reported that in an environmental chamber with an atmosphere enriched by 15N indicated, white clover did not rapidly transfer nitrogen to associated ryegrass. The plants were mycorrhizal.

Non-N Nutrient Contribution

Tan and Crabtree (1990) reported that perennial ryegrass sod led to reduced foliar concentration of N, S, Ca, B, and Mn in 'Chardonnay' wine grape vines. Mowing the grass did not alleviate the competition.

Effects on Water

Theiss (1990) reported that after high initial rates of N fertilization, perennial ryegrass does not appear as efficient at N uptake as are annual ryegrass and cocksfoot (Dactylis glomerata). However, the release of nitrogen from perennial ryegrass swards apparently takes place later in the autumn than for the other two grasses. Thick stands of grasses (perennial ryegrass, annual ryegrass, and cocksfoot [Dactylis glomerata]) are more effective at N uptake than are open stands. Drought stress reduced N uptake by annual ryegrass more than by perennial ryegrass or cocksfoot.

In Wales, Mytton et al. (1993) evaluated the differential effects on soil structure and water infiltration of monocultural swards of white clover and perennial ryegrass and a mixture of the two. The replicated study employed undisturbed soil cores (100 mm i.d. x 180 mm length; silt loam acid brown earth) extracted from the field and arranged in a greenhouse. White clover stands led to greater water infiltration, 43.1g/4h, vs. 32.9 for annual ryegrass, vs. 39.4 for mix. Apparent greater soil friability in the clover cores was not reflected in soil bulk density of % soil aggregates >2mm upon wet sieving. Total porosity was little changed, but air-filled (macroporosity) was as follows: clover > mix > perennial ryegrass.

Effects on Microclimate

Newenhouse and Dana (1989) reported a three-year field study of strawberry (Frageria X ananassa Duchesne, Rosaceae, cv 'Sparkle' and 'Honeoye') showing that living mulches of wheat (Triticum aestivum L.), Kentucky bluegrass (Poa pratensis L.), or perennial ryegrass (Lolium perenne L.) provided protection from winter storms, and thereby improved fruit yield and quality. When snow covered the strawberry plants, living mulches did not enhance yield or quality. When wind damaged blossoms, yields were better in plots with living mulches. When no such damage occurred, yields did not differ. Perennial ryegrass, which spreads by tillering but did not invade the strawberry rows, and which grows tall enough to provide wind protection, appeared to be the best living mulch tested.

Effects on Soil

Eight- and fifteen-year-old swards of perennial ryegrass contained on average 68 kg/ha of above-ground nitrogen (stubble), 12 kg/ha of nitrogen in litter, 249 kg/ha nitrogen in root biomass, and 240 kg/ha of nitrogen in soil macro-organic matter (Whitehead et al., 1990).

Increased efficiency of N-uptake could have important ramifications in avoiding excess leaching of nitrates. Studies by Wilkins and Lovatt (1989) in Wales indicate that the newest variety of perennial ryegrass, Ba 10761 gave a 20% higher yield of nitrogen than did the oldest, S.321. Nitrogen was applied at three rates: 0.6, 0.4, and 0.2 t/ha. Overall mean proportions of nitrogen recovered over nitrogen applied were as follows for the four varieties tested Ba 10761: 0.62, Talbot: 0.57, Tove: 0.56, and S.321: 0.51.

Theiss (1990) reported that after high initial rates of N fertilization, perennial ryegrass does not appear as efficient at N uptake as are annual ryegrass and cocksfoot (Dactylis glomerata). However, the release of nitrogen from perennial ryegrass swards apparently takes place later in the autumn than for the other two grasses. Thick stands of grasses (perennial ryegrass, annual ryegrass and cocksfoot [Dactylis glomerata]) are more effective at N uptake than are open stands. Drought stress reduced N uptake by annual ryegrass more than by perennial ryegrass or cocksfoot.

In Germany, winter crops of rape, barley, and Welsh ryegrass respectively accumulated in their above-ground structures 52.1, 36.2, and 22.9 kg N/ha following bell bean (cv 'Alfred') (Raderschall and Gebhardt, 1990).

A three-year field study of strawberry (Frageria X ananassa Duchesne, Rosaceae, cv 'Sparkle' and 'Honeoye') showed that living mulches of wheat (Triticum aestivum L.), Kentucky bluegrass (Poa pratensis L.), or perennial ryegrass (Lolium perenne L.) reduced soil compaction (Newenhouse and Dana, 1989).

In Wales, Mytton et al. (1993) evaluated the differential effects on soil structure and water infiltration of monocultural swards of white clover and perennial ryegrass and a mixture of the two. The replicated study employed undisturbed soil cores (100 mm i.d. x 180 mm length; silt loam acid brown earth) extracted from the field and arranged in a greenhouse. White clover stands led to greater water infiltration, 43.1g/4h, vs. 32.9 for annual ryegrass, vs. 39.4 for mix. Apparent greater soil friability in the clover cores was not reflected in soil bulk density of % soil aggregates >2mm upon wet sieving. Total porosity was little changed, but air-filled (macroporosity) was as follows: clover > mix > perennial ryegrass.

Effects on Livestock

Very palatable to livestock. (Fred Thomas, pers. comm.)

Pest Effects, Nematodes

Perennial ryegrass harbored particularly low densities of root lesion nematode (Pratylynchus penetrans) in an orchard in Ontario, Canada (Marks and Townsend, 1973).

Pest Effects, Weeds

When seeded along with legumes or some other grasses, annual and perennial ryegrasses contribute to better control of weeds (Miller, 1984).

A three-year field study of strawberry (Frageria X ananassa Duchesne Rosaceae; cv 'Sparkle' and 'Honeoye') showed that living mulches of wheat (Triticum aestivum L.), Kentucky bluegrass (Poa pratensis L.), or perennial ryegrass (Lolium perenne L.) effectively suppressed weeds. Perennial ryegrass, which spreads by tillering but did not invade the strawberry rows, and which grows tall enough to provide wind protection, appeared the best living mulch tested (Newenhouse and Dana, 1989).