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Kura Clover

Contributor: Norman L. Taylor

Common Names
Scientific Names
Uses
Origin
Crop Status
Botany
1. Taxonomy
Crop Culture
1. Cultivars
2. Production Practices
Germplasm
1. Collections
2. Commercial Seed Sources
Key References
Selected Experts

Common Names

USA: Pellet's clover, honey clover, kura clover
Australia & New Zealand: caucasian clover
Other languages: unknown

Scientific Names

Species: Trifolium ambiguum Bieb
Family: Leguminosae (Fabaceae)

Uses

Cultivated as a forage legume for grazing. Formerly some usage as a source of nectar for honey production.

Origin

Caucasian Russia, Crimea, and Asia Minor

A strong perennial spreading by rhizomes. It is receiving some interest in USA, New Zealand, and Australia for use in pasture mixtures. It is apparently quite nutritious and persists many years in mixtures with grasses. Persistency is due in part to its heavy root biomass; up to 20 metric tons/ha. Root:shoot ratios in a 13 -year old stand were reported to be up to 4.6:1. Little or no domestic use occurs in countries of origin. In USA, livestock producers have sown very few acres primarily because of seed limitations. The cultivar Rhizo is being increased by commercial seed companies.

Botany

Taxonomy

The species is classified by most authorities in section Lotoidea, subsection VII Platystylium of the genus Trifolium. Three ploidies occur; diploid, tetraploid, and hexaploid, which are reproductively isolated. Hexaploids are generally, but not always, the most vigorous but cultivars have been developed at each ploidy level. Kura clover is closely related to T. repens and T. hybriduum with which it has been hybridized. Kura, like most perennial clovers, is self-incompatible, requiring cross-pollination by bees (honey, bumble, leafcutter, alkali) to produce seeds. The yellow brown seeds are about 1.2 mm long and average about 670/g, roughly the same size as red clover (T. pretense) and larger than white clover (T. repens). Corolla is white to pale pink turning flesh colored after anthesis. Typical legume inflorescences are grouped into heads, usually upright but with the lower ones deflexed. Pods are 1 to 2 seeded.

Crop Culture

Kura clover is adapted to about the same latitude as its origin, about 40 to 50 degrees. Consequently, it is very cold hardy and tends to be more productive in cooler than in warmer climates. However, breeding efforts are being made to extend its area of usage southward in the U.S., and northward in New Zealand. The clover performs best on well drained, fertile soil but may survive occasional swamping, and lower pH (5.0-6.0) than other forage legumes. During droughts in southern U.S., it tends to go dormant in the summer producing very little growth until moisture becomes available in the fall. The primary difficulty of the crop is slow seedling establishment. It generally flowers only once per season, but cultivars differ.

Cultivars

Cultivars or breeding populations (some not yet released) may be classified as to ploidy and country of release. They include:

Australia: Alpine (2X); Summit (2X); Forest (2X); Treeline (4X); Prairie (6X)
New Zealand: Manaro (6X); KZ-2 (6X)
USA: Rhizo (6X); Cossack (6X)

Production Practices

In central and northern US., kura clover is usually sown in a similar fashion as other small seeded perennial legumes, in the spring, on a well prepared seed bed. Because of low seedling vigor it is mandatory to sow it without companion grasses or small grains. Renovation sowings are not recommended. Optimally, pH and fertility should be adjusted prior to sowing based on soil tests. Special inoculation is required because only one Rhizobium strain specific to kura clover is effective, and pains should be taken to assure that inoculation is effective. Some investigators claim that special seed coating techniques are helpful. Seeding rate probably should be 12 to 15 kg/ha. The use of herbicides such as balan, treflan, preincorporated to control weeds is necessary, and if weeds develop later it is necessary to control them with appropriate herbicides (Poast, Basagran, or Fusilade). Failure to control competition may result in stand failure. Very little growth is expected in the first season and flowering in most cultivars does not occur until the second season after induction by low temperature in the winter. Flowering in the next season will occur in early May in central U.S. If seed is to be produced, this flowering crop must not be removed as abundant flowering occurs only once per season. If saved for seed, yields may be expected to be 100 to 200 kg/ha. The primary usage of the forage is for grazing, and it may be desirable to sow grasses after the kura is established. In the central bluegrass region of the U.S., bluegrass may invade the clover stand, ultimately resulting in a mixture. Kura stands are slow to establish but, once established, may be expected to last indefinitely, depending upon management, because of its large root biomass. Rotational grazing may be more productive than continuous grazing.

Germplasm

Collections

USDA Western Regional Plant Introduction Station, Pullman, Washington.

USDA Curator location: Department of Agronomy, University of Kentucky, Lexington, KY.

Commercial Seed Sources

Norfarm Seeds, Inc., PO Box 725, Bemidji, MN 56601, USA.

Peterson Seed Company, Inc., PO Box 346, Savage, MN 55278, USA.

Key References

Dear, B.S. and M. Zorin. 1985. Persistence and productivity of Trifolium ambiguum, caucasian clover in a high altitude region of southeastern Australia. Aust. J. Exp. Agric. 25:124-132.
Evans, A.M. and D.G. Jones. 1966. The response to inoculation of three chromosome races of Trifolium ambiguum sown with and without a companion grass. I. The effect of inoculation on yield of clover and grass. J. Agric. Sci. 66:315-319.
Speer, G.S. and D.W. Allinson. 1985. Kura clover (Trifolium ambiguum): Legume for forage and soil conservation. Econ. Bot. 39:165-176.
Strachan, D.E., A.H. Nordmeyer, and J.G.H. White. 1994. Nutrient storage in roots and rhizomes of hexaploid caucasian clover. New Zealand Grassl. Assoc. Proc. 56:97-99.
Taylor, N.L. and P.L. Cornelius. 1994. Influence of recurrent selection for flowering on flowering and yields in kura clover. Euphytica 72:9-14.

Selected Experts

Norman L. Taylor, Dept. of Agronomy. Agricultural Sciences Bldg. N., University of Kentucky, Lexington KY 40546-0091. Tel. 606-257-5785; Fax 606-323-1952; E-Mail:
AGRO79@UKY.EDU.

Richard R. Smith, Dairy Forage Research Center, University of Wisconsin, Madison, WI. Tel. 608-264-5279; Fax 608-264-5275; E-Mail:
Clover@DFRC.WISC.EDU.

Last update Tuesday, February 24, 1998 by aw