Trifolium pratense L.
Red clover, Peavine clover, Cowgrass
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
Extensively grown for pasturage, hay and green manure, considered excellent
forage for livestock and poultry. Compared with alfalfa, red clover has about
two-thirds as much digestible protein, slightly more total digestible
nutrients, and slightly higher net energy value. The best approximation to
vegetable boullion I ever made consisted of red clover and chicory flowers,
boiled vigorously with wild onion and chives. Red-clover flowers are reported
to possess antispasmodic, estrogenic, and expectorant properties. The solid
extract is used in many food products, usually at less than 20 ppm, but in jams
and jellies, it may be 525 ppm (Duke, 1984b).
Said to be used for: alterative, antiscrofulous, antispasmodic, aperient,
athlete's foot, bronchitis, burns, cancer, constipation, diuretic, expectorant,
gall-bladder, gout, liver, pertussis, rheumatism, sedative, skin, sores, tonic,
and ulcers. Flowers have been used as a sedative. Russians recommend the herb
for bronchial asthma. Chinese take the floral tea as an expectorant. Kloss
recommends that every family "stash" red clover blossoms, gathered in summer,
and dried on paper in shade. "Use this tea in place of tea and coffee and you
will have splendid results." This is one of Kloss' diets that doesn't offend
me. Pages have been devoted to the anticancer activity of the floral tea, a
remedy not yet tested by the National Cancer Institute. Herbals recommend
clover for bronchitis, leprosy, pertussis, spasms, and syphilis. Jason Winters
tea, containing red clover and chaparral and some unidentified secret spice,
sells at rather high prices as a "cancer cure" (Duke, 1984b).
Seeds are reported to contain trypsin inhibitors and chymotrypsin inhibitors.
Green forage of red clover is reported to contain: 81% moisture, 4.0% protein,
0.7% fat, 2.6% fiber, 2.0% ash. Hay of red clover contains 12.0% moisture,
11.8% protein, 2.6% fat, 27.2% fiber, and 6.4% ash. On the basis of more than
500 analyses, Miller (1958) reported the hay contained on a moisture free
basis: 8.324.7% protein (avg 14.9%), 1.06.6% fat (avg. 2.9%), 12.539.3%
crude fiber (avg. 30.1%), 3.114.0% ash (avg. 7.9), and 33.459.1% N-free
extract (avg. 44.2). For green red clover forage he reported 12.434.87.
protein (avg. 18.2), 3.25.9% fat (avg. 4.0%), 12.730.8% crude fiber (avg.
24.2), 7.013.6% ash (avg. 8.8), and 37.149.7% N-free extract (avg. 44.8%).
The hay (dry matter averaging 87.7%) contained 0.972.29% Ca (avg. 1.61),
0.090.45% P (avg. 0.22), 0.572.67% K (avg. 17.6%), 0.240.81% Mg (avg.
0.45%), 0.0010.185% Fe (avg. 0.013%), 9.917.6 ppm Cu (avg. 11.2 ppm), and
24.9120.8 ppm Mn (avg. 65.6). The green forage contained 0.583.21% Ca (avg.
1.76), 0.240.53% P (avg. 0.29), 1.492.94% K (avg. 2.10%), 0.360.57% Mg (avg.
0.45), 0.0160.032% Fe (avg. 0.03), 7.3-10-3 ppm Cu (avg. 8.8 ppm), 121464 ppm
Mn (avg. 159 ppm). The leaf-protein concentrate (59% protein) contains 6.4%
arginine, 2.5% histidine, 5.4% threonine, 1.7% tryptophan, 9.5% leucine, 5.3%
isoleucine, 1.7% methionine, 6.87. lysine, 6.1% phenylalanine, and 6.8%.
valine. Estrogenic disorders have been reported in cattle grazing largely on
red clover, apparently due to activity of the isoflavones formononetin,
biochanin A, and to some small extent daidzein and genistein. the flowers
contain a number of phenolic compounds: daidzein, genistein, isotrifolin,
isorhamnetin, pratol, pratensol, trifolin, and an antifungal compound
trifolirhizin. They also contain coumaric acid, hentriacontane, heptacosane,
myricyl alcohol, and b-sitosterol. On a dry basis flowers yield 0.028% of
an oil containing furfural (Duke, 1981a).
Perennial, sometimes biennial, legume, sparingly pilose to glabrous, sometimes
densely pilose [forma pilosum (Griseb.) Hayek]; stems erect or
ascending, 15 cm long; leaves of basal rosette all long-petioled, those of
stem moderately long-petioled to nearly sessile; leaflets oval or elliptic to
cuneate-obovate, 13 cm long, 0.51.5 cm broad, subentire; stipules oblong-oval
to oval-triangular, the free part broadly triangular, abruptly tapering to an
erect setaceous tip; peduncles short or absent; heads mostly terminal, sessile,
short-peduncled, usually closely subtended by the stipules of the upper pair of
leaves, dense, subglobose to ovoid, 1.23 cm long; flowers sessile, 1015 mm
long, rosy purple to creamy-white (forma leucochraceum Aschers. &
Prantl), erect; calyx-tube campanulate, narrower at base, 10-nerved, pubescent
including the inner margin of the throat,.the teeth filiform from a triangular
base, sparsely hirsute, porrect, the upper about equaling the tube, the lower
almost twice as long; corolla about twice the length of the calyx; pods
oblong-ovoid, circumscissile; seeds ovoid, asymmetrical, yellowish to purplish.
Seeds ca. 600,000/kg; wt. kg/hl = 77 (Duke, 1981a).
Red clover cvs are of two typesearly-flowering cvs that produce at least two
cuttings per season, and late-flowering cvs that produce one cutting per
season. Early-flowering cvs, also called medium or double-cut, are the most
common type grown in the United States. Late-flowering cvs, called mammoth or
single-cut, are grown where the growing season is short, as in high elevations
or latitudes. Several cvs of both types are available. Taylor and Smith (1981
discuss a few of the more promising cvs. The cvs are rather limited in their
areas of adaptation. Assigned to the Eurosiberian Center of Diversity, red
clover, or cvs thereof is reported to exhibit tolerance to aluminum, disease,
frost, fungus, grazing, hydrogen floride, high pH, low pH, mines, mildew,
myco-bacteria, slope, virus, waterlogging, and weeds. (2n = 14, 28.)
Native to north Atlantic and central Europe, the Mediterranean region, Balkans,
Asia Minor, Iran, India, Himalayas, Russia from Arctic south to east Siberia,
Caucasus, and the Far East. It spread to England ca 1650 and was carried to
America by British colonists (Taylor and Smith, 1981). Widely introduced and
Native on wet to dry meadows, open forests, forest margins, field borders, and
paths. Grows best on well-drained loam soil, but also adapted to wetter soils.
Most soils that produce good crops of corn, tobacco or small grains will also
produce a good crop of red clover. Loams, silt loams, and even fairly heavy
soils are better than light sandy or gravelly soils. Some of these soils may
need lime or fertilizer, or both. Red clover is most productive on soil that
is within a pH range of 6.6 to 7.6. It also needs P and K to produce good
yields; amounts needed can be determined by soil tests. Ranging from Boreal
Moist to Wet through Subtropical Moist Forest Life Zones, red clover is
reported to tolerate annual precipitation of 3.1 to 19.2 dm (mean of 91 cases =
8.6 dm), annual mean temperature of 4.9 to 20.3°C (mean of 91 cases =
10.6°C), and pH of 4.5 to 8.2 (mean of 84 cases = 6.3). Maximum yields
obtained at pH >6 with adequate calcium. A photoperiod of at least 14 hours
seems necessary for the double-cut type to flower, 1618 hours for 'Mammoth'
(Taylor and Smith, 1981; Duke, 1978).
In northeastern United States and Canada, and at higher elevation in
southeastern and western United States, red clover grows as a biennial or
short-lived perennial; at lower elevations in southeastern United States, it
grows as a winter annual, and at lower elevation in western United States and
Canada, it grows under irrigation as a biennial. Most red clover is spring
seeded in a crop of fall- or spring-sown small grain. In the early spring the
soil alternately freezes and thaws, thus covering the seed with soil. The
small grain holds weeds in check while the clover is getting started. At lower
elevations in southeastern and western United States, red clover is sown ca
Oct. 15, no later than Dec. 15. In these areas it is most frequently sown
without a companion crop. In south-eastern United States, late-summer
seedlings can be successful on a seedbed, fallowed to prevent weed growth.
Grass is extensively seeded with red clover. Clover-grass mixtures are usually
superior to clover. In vitro and vivo experiments show that some lines of red
clover perform better with ryegrass (Lolium multiflorum). Clover-grass
yields better hay that cures more rapidly than pure clover hay. Animals are
more likely to bloat on pure clover than on clover-grass pasture. Timothy has
a high yield, and is ready to cut for hay with the red clover. Sow the grass
in the early fall in the small-grain crop; sow the red clover in the small
grain-grass in the spring. When the grain is harvested, remove the straw and
stubble, as they tend to smother the clover and favor disease. Clover-hay
yields from fields where the straw and stubble have been left are only about
one-half as large as the yields from fields where they have been removed
immediately after combining. Small-grain companion crops compete with red
clover for mineral nutrients, moisture, and light. This competition can be
reduced by grazing or clipping the small grain in late winter or early spring,
just before stems begin growth., Grazing or clipping after clover stems have
begun to branch will reduce small-grain yield.
The first year, graze or mow the clover 4 to 6 weeks before the first frost in
the fall. If the stand is mowed, remove the clippings unless the total amount
is quite small. The first crop of red clover, harvested early the second year
is almost always harvested for hay or silage. In early bloom, red clover is
leafy and produces its largest yield of protein per hectare. Cut red clover
about 15 days after the first blooms appear. Cut stands grown with grass when
clover is ready, not when grass is ready. Usually the second crop of red
clover is pastured, harvested for seed, or grown for soil improvement and green
manure. To harvest for hay, cut in early bloom; however, hay from this crop is
occasionally unpalatable to cattle and sheep. A medium stand of red clover
will produce two or three crops of hay the harvest year. Mammoth clover will
produce one crop. After the crop is cut, allow it to wilt in swath and then
rake it into small, loose windrows. It will cure about as rapidly in the
windrows as in the swath, and fewer leaves will be lost in baling. Better, it
can also be forced-air dried, which preserves the green color, lessens leaf
shattering, and practically eliminates spoilage. Red clover and red
clover-grass mixtures are frequently ensilaged. These crops make good ensilage
if they are wilted slightly before ensiled, or if carbohydrate or chemical
preservatives are added as they are ensiled. Red clover is one of the best
legume pasture plants for livestock and poultry. Red clover and red
clover-grass mixture pastures can be grazed or they can be cut green and fed to
livestock and poultry. Red clover is also one of the better legumes for
renovating old pastures. Clip or graze the old pasture closely. Chop up the
sod with a disk or harrow before sowing the red clover seed. Red clover may be
turned under as green manure to improve soil properties and increase yields of
succeeding crops. Many crop rotations are possible for red clover, the oldest
being a 3-year rotation of corn, oats or wheat and red dover. Other common
rotations are: corn, soybeans, small grain, red clover; corn, small grain, red
clover, rice, red clover; sugar beets, small grain, red clover; tobacco, rye or
wheat, red clover-grass, grass, grass; potatoes, small grain, red clover. For
seed production, the first crop of the second-year stand is usually harvested
for hay or silage, the second crop may be harvested for seed. In most areas it
is necessary to pollinate with bees, using 5 to 8 strong colonies of bees per
hectare. Best seed yields occur when there is an abundance of bees, and soil
fertility and moisture are adequate to promote good growth, and when the
weather is warm and clear during the flowering period. Harvest the seed crop
when the greatest number of seed heads are brown, usually 2530 days after full
bloom. Cut seed crop with mower. Let it cure in the swath or in small
windrows. During rainy weather, the mowed crop cures better in swaths than in
windrows. Windrowing is better during clear, warm weather because it reduces
harvesting losses. Harvest the swathed or windrowed crops with a combine with
a pickup attachment. Operate combine carefully to do a good harvesting job and
to reduce harvesting losses. Artificial drying or drying by spreading seed
thinly on a floor may improve the quality of the seed. Seed should be turned
every few days until completely dry. Rough cleaning immediately after
combining reduces the drying time and improves seed quality.
Under favorable conditions, seed yields average about 7097 kg/ha, but under
irrigation in western United States may reach 600800 kg/ha. Polish seed
yields range from 250500 kg/ha (Wawryn, 1978). Several cvs of red clover, as
'Kenland', 'Pennscott', 'Dollard', and 'Chesapeake', where adapted, produce
higher yields of forage and are more persistent than common red clover.
Depending upon stage at which red clover is cut for forage, hay, or silage,
yields vary from 900 to 19000 kg/ha. Red clover is the most Widely grown of
the true clovers and forms one of the most important hay crops in temperate
regions, especially when combined with grasses. In 1970, about 24,000 MT of
red clover seed were produced on about 200,000 hectares, mainly in California,
Iowa, Oregon, Kansas, and Virginia. Value of the seed crop is estimated around
$23 million. In 1976, red clover hay averaged $66.44/MT. Assuming that 21.5
million MT of hay are produced annually, the economic value of the red clover
hay alone is worth $1.4 billion per year or $265/ha. This ignores the
significant value of pasture in red clover (Taylor and Smith, 1981).
Duke's phytomass files cite DM yields of 619 MT from such places as Romania,
Switzerland, and the USSR. Finnish DM yields for 390 cvs ranged from 0.211.8
MT/ha (Ravantti, 1980). Belgians got 7 MT/ha from pure clover, nearly 13 MT
intercropped with grasses (Andries, 1982). In Michigan, red clover cvs
averaged 6.57.4 MT/ha compared with 10.3 for alfalfa and 6.2 for birdsfoot
trefoil. Most of these figures are experiments. Taylor and Smith (1981)
suggest that production yields, even in the US are lower: red clover with
timothy yield about 21.5 million MT per year or closer to 4 MT/ha, pure red
clover closer to 3 MT. It is estimated that red clover will provide 125200
kg/ha N for use by subsequent crops. Taylor and Smith tabulate data suggesting
that it takes ca 50,000 million Btu to produce 1 kg beef on feed lot pink
clover, 45,000 million on haylage, and 40,000 million on grazing/feeding, the
biggest, input, fertilizer being the biggest energetic input (ca 450 million
Btu for lime, 540 for fertilizer), fuel (200 million for pasture, 420 for
feedlot), and ca 130230 million Btu for machinery, manufacture, transport, and
repairs. Even residues are estimated at ca 4 MT/ha by Kvech (1979). Reducing
Kvech's numbers by 10% to convert approximately to DM yields for residues, we
have the following figures for Kourim, Czechoslovakia, rounded to the nearest
MT: Medicago sativa, 7; Trifolium pratense, 4; Vicia faba,
4; Avena sativa, 3; Lolium perenne, 3; Secale cereale, 3;
Trifolium repens, 3; Triticum aestivum, 3; Brassica rapa,
2; Hordeum vulgare, 2; Phacelia tanacetifolia, 2; Beta
vulgaris, 1; Sinapis alba, 1; Solanum tuberosum, 1. Yields
of other clover species reported in the Phytomass File are 211 for T.
alexandrinum, 45 for T. hirtum, 7 for T. hybridum, 1252 for
T. incarnatum, 27 for T. repens, 911 for T. resupinatum,
813 for T. subterraneum, and 2 for T. vesiculosum. The USDA
(1983) reported yields of 0.552 MT DM/ha/yr with N-fixation of 46418 kg in
Duke (1981a) lists many fungi, insects and nematodes plaguing red clover. Red
clover is attacked by many fungi, some of which may cause serious losses.
Among the fungi: Alternaria tenuis, Ampelomyces quisqualis, Ascochyta
trifolii, Botrytis anthopila, B. cinerea, Brachysporum trifolii, Cerospora
zebrina (summer black stem), Chaetomium cochliodes, Colletotrichum
destructivum, C. trifolii (southern anthracnose), Corticium solani,
Cylindrocladium scoparium, Cymadothea trifolii, Didymella trifolii, Didymium
sturgisii, Erysiphe communis f. trifolii, E. martii, E. polygoni
(powdery mildew), Fusarium acuminatum, F. avenaceum, F. equiseti, F.
gramineaum, F. oxysporum (root rot), F. pose, F. roseum, F. solani,
Kabatiella caulivora (northern anthracnose), Leptosphaerulina americana,
L. briosiana, L. trifolii, Metasphaeria boucera, Microsphaeria alni,
Mycosphaerella carinthiaca, Oidium erysiphoides, Ophiobolus collapsus, O.
graminis, Peronospora pratensis, P. trifoliorum, Phoma trifolii (spring
black stem), Phyllachora trifolii, Phymatotrichum omnivorum, Phytophthora
cactorum, Phyllosticta trifolii, Plenodomus melioti, Pleospora herbarum,
Polythrincium trifolii, Pseudopeziza trifolii, Pseudoplea medicaginis, P.
trifolii (pepper spot), Pyrenopeziza jonesii, Pythium debaryanum,
Rhizoctonia crocorum, Rh. leguminicola (black patch), Rh. solani, Rh.
violacea, Sclerotinia kitajimana, S. sclerotiorum, S. spermophila, S.
trifoliorum (crown rot), Septoria compta, Sporonema phacidioides, S.
trifolii, Sphaerulina trifolii, Stagonospora compta, S. meliloti, S. recedens,
Stemphylium sarcinaeforme (target spot), S. botryosum, Sclerotium
delphinii, S. rolfsii, S. bataticola, Stictus pustulata, Thielaviopsis
basicola, Thyrospora sarcinaeformis, Uromyces fallens, U. minor, U.
nerviphilus, U. trifolii, U. trifolii-repentis, Vermicularis dematium,
Verticillium dichotomum, and Volutella fusarioides. Red clover's
life cycle may be shortened by buildups of Fusarium, Gliocladium, and
Rhizoctonia in the soil. Since it is impractical to control diseases
with fungicides, stress is placed on finding or developing disease resistant
cvs. Bacteria causing diseases in red clover include: Bacillus lathryi
(red clover streak), Pseudomonas radiciperda, and Ps. syringae.
Parasitic on red clover are Cuscuta epithymum and C. pentagona.
Viruses causing diseases in red clover include the following: bean yellow
mosaic (BYMV), red clover vein mosaic (Marmor trifolii), clover mosaic,
Pisum virus 2, lucerne mosaic, Trifolium virus 1, common pea mosaic, clover
phyllody virus, rugose leaf curl, tobacco mosaic, white clover mosaic, and
potato calico (Marmor medicaginis var. solani). The most
promising method for control of many red clover diseases is development of
resistant cvs. Some progress has been made in developing cvs resistant to
northern and southern anthracnose and powdery mildew. For control methods,
local agents should be consulted. Nematodes isolated from red clover include:
Acrobeles ciliatus, Acrobeloides emarginatus, Aphelenchoides ritzemabosi,
Aphelenchus avenae, Boleodorus thylactus, Cephalobus spp.,
Chiloplacus spp., Criconemella curvata, C. lobata, C. rustica,
Ditylenchus destructor, D. dipsaci, Eucephalobus spp., Helicotylenchus
cairnsi, H. canadensis, H. digonicus, H. dihystera, H. multicinctus, H.
pseudorobustus, Heterodera davertii, H. glycines, H. goettingiana, H.
lespedezae, H. trifolii, Hoplolaimus galeatus, H. tylenchiformis, Longidorus
elongatus, L. maximus, Meloidogyne arenaria, M. artiellia, M. hapla, M.
incognita, M. i. acrita, M. javanica, Merlinius brevidens, M. macrurus,
Neotylenchus spp., Paratylenchus aciculus, P. brevihastus, P. hamatus,
P. projectus, P. sarissus, P. tenuicaudatus, Pratylenchus brachyurus, P.
coffeae, P. neglectus, P. penetrans, P. pratensis, P. scribneri, P. tumidiceps,
Psilenchus hilarulus, Pungentus pungens, Rotylenchulus reniformis, Rotylenchus
goodeyi, R. robustus, Scutellonema brachyurum, Trichodorus christiei,
Tylencholaimus mirabilis, Tylenchorhynchus agri, T. annulatus, T. claytoni, T.
dubius, T. maximus, T. parvus, Tylenchus costatus, T. davainii, and
Xiphinema americanum. Amosu and Taylor (1975) showed that
Tylenchorhynchus agri, which feeds only on the epidermal cells in the
region of root elongation, actually stimulates the growth. The most
destructive insects reported on red clover include the following: clover root
borer (Hylastinus obscurus), clover root curculio (Sitona
hispidulus), clover seed chalcid (Bruchophagus gibbus), lesser
clover leaf weevil (Hypera nigrirostris), potato leafhopper (Empoasca
fabae), yellow clover aphid (Therioaphis trifolii), meadow
spittlebug (Philaenus spumarius), clover seed midge (Dasineura
leguminicola) clover leafhopper (Aceratagallia sanguinolenta), and
pea aphid (Acyrthosiphon pisum). "No practical controls of these
insects are available." (Taylor and Smith, 1981). Red clover is pollinated by
honeybees and bumblebees.
Complete list of references for Duke, Handbook of Energy Crops
- Amosu, J.O. and Taylor, D.P. 1975. Stimulation of growth of red clover by
Tylenchorhynchus agri. Indian J. Nematology 4(2):132137.
- Andries, A. 1982. The role of red clover in Belgian forage production: Changes
and perspectives. Fourrages No. 90:2737.
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 161. In: ASA Special
Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron.
- Duke, J.A. 1981a. Handbook of legumes of world economic importance. Plenum
- Duke, J.A. 1984b. Borderline herbs. CRC Press. Boca Raton, FL.
- Kvech, O. 1979. The importance of crop residues in rotations of an intense
farming system. Rostlinna Vyroba 25(10):10131022. (abstract only)
- Miller, D.F. 1958. Composition of cereal grains and forages. National Academy
of Sciences, National Research Council, Washington, DC. Publ. 585.
- Ravantii, S. 1980. Winter hardiness and yield of local varieties of Finnish red
clover grown in Southern Finland at the Anttila experimental farm of the
Hankkija Plant Breeding Institute in 19626. Ann. Agr. Fenniae 19(2):142155.
- Taylor, N.L. and Smith, R.R. 1981. Red clover Trifolium pratense. p.
1121. In: McClure, T.A. and Lipinsky, E.S. (eds.), Handbook of biosolar
resources. vol. II. Resource materials. CRC Press, Inc., Boca Raton, FL.
- USDA. 1983. Crop production research. Agricultural Research Service 1982 Annual
- Wawryn, T. 1978. The influence of Alar 85 on the flower structure and seed
yield of tetraploid red clover. Bul. Inst. H.I.A. Roslin 134:107113.
Last update Friday, January 9, 1998 by aw