Common name : Puncture vine, burnut, caltrop
Common name in Hindi : Bhakri, chota gokhru, ground bur-nut, kanti
Common name in Urdu : Bhakhra
Bangla English Hindi Urdu
Diagnostic characters
Biology
Ecology and distribution
Nuisance
Weed control
Botany
Uses/Remark
References
Tribulus terrestris forms herbaceous annual mat by its prostrate to decumbent habit and a long taproot. The stems, green to reddish or brownish and pubescent, radiate from a central axis; the leaves are compound and have an opposite arrangement, each leaf has five to eight pairs of unequal leaflets, the upper surface of the leaves are green and sparsely pubescent while the lower surface is whitish and densely pubescent. The flowers have five yellow petals and the fruit split when mature into five woody and spiny segments. This character is said to be at the origin of the genus name Tribulus; it derives from the Latin Tribo, that means “to tear”. In India T. terrestris is used in traditional medicine as a tonic, diuretic and as an aphrodisiac plant.
T. terrestris is a summer annual plant in the most temperate areas and it may become a perennial under suitable tropical conditions. As the plant has a deep, somewhat woody taproot and a network of fine rootless, it can obtain the moisture and grows under conditions much rigorous for most plants. It reproduces only by seeds. The seeds germinate irregularly throughout the year and do not seem to have specific germination requirements enabling the plant to develop anywhere. In India the weed after it has germinated, grows very rapidly and can cover a large area within a week. Flowering starts about 3 to 5 weeks after germination when the maximum shoots growth occur. Flowers usually remain on the plant about 2 weeks before fruiting formation starts. Fruits mature in about 2 weeks, splitting apart into segments soon thereafter. One plant can covers about 2.5 sq m and produces 1000 fruits.
T. terrestris is distributed over the world from 35° S to 47° N. Probably native to the Mediterranean region, this weed is now widespread in tropical to temperate regions like southern Europe, eastern Africa, southern Asia and Australia. The seeds of T. terrestris may have been disseminated across the world in the wool of European sheep. The weed is usually reported first near agricultural communities, railroad yards, or costal towns.
This weed grows best in dry, loose, sandy soils and prospers in field margin. However it also grows in heavier soils, especially if they are fertile and moist. It can also grow on compact soils.
The problems and losses due to T. terrestris are: 1) flesh and skin punctures, infections and other mechanical injuries to animals, 2) reduced crop seed quality, 3) increased harvesting costs, 4) increased costs of land preparation and weed control and 5) since the whole plant contains a toxic substance is harmful to livestock when used as feed. It is a common weed of cereals, pastures, peanuts, sugarcane, coffee, onions, fiber, fruits and potatoes crops. T. terrestris is a problem in crops because of its ability to extract soil moisture from great deep in the soil becoming a severe competitive plant in very dry conditions. In India was the dominant weed in pearl millet (Pennisetum typhoides, causing a 15 to 20 percent loss in grain yield. In the arid zone of India, where 4 to 9 percent of the surface of cultivated fields is covered by this weed, it indicates overgrazing and declining soil fertility. It has been reported that as much as 30 percent of the maize fields of Punjab (India) are infested with this weed.
- Cultural
We must first look to seeds destruction or prevention. Because the seeds germinate irregularly throughout the year and because the plants can flower and set seeds in such a short time, single or infrequent cultivations will not be sufficient to reduce seeds populations. As the plant has a taproot, shallow cultivation to sever the taproot just below the soil surface is probably best. Deep plowing appears to have little advantage because the seeds have a long life in the soil. If fruits have formed, plant should be cut so that seeds can not ripen.
- Chemical
Post-emergence application of 2_4-D at 500 g/ha or Almix at 4g/ha.
Habit
Is a prostrate to decumbent, mat-forming weed. Although T. terrestris is normally a prostrate plant, it may grow almost upright when competition and shading occur in dense crop stands.
Roots
Strong taproot with a large network of fibrous lateral rootless.
Stem
Much branched and radiating from a central axis to around 3 m long, green to reddish or brownish, striate, pubescent and finely or stiff white hairy, sometimes sparsely hairy.
Leaves
Opposite, compound, pinnate, short petiolate, larger leaves up to 6cm long, smaller up to 3.5cm long; leaflets in five to eight (rarely in 14) pairs, usually unequal with one pair being shorter than the other, rachis densely pubescent, leaflets obliquely oblong-lanceolated up to 15mm long, 5mm wide, upper surface green, sparsely pubescent, lower surface whitish with dense pubescent; stipules linear, up to 10mm long.
Inflorescence
Flowers solitary, axillaries, on pubescent pedicels slightly shorter than the leaves below; sepals 3 to 5mm long, acute; petals five, pale yellow, 3 to 12mm long; stamens about as long as the petals.
Fruit
Capsule like about 1cm in diameter with five indehiscent, approximately triangular, dry, almost woody segments (cocci) disposed like a star, which split when mature; cocci pubescent or almost glabrous, each with a tuberculate bristly dorsal crest, two tough lateral divergent acute spines above the middle, and two shorter spines near the base, directed downward.
Seeds
One to five in each segment, whitish, flattened, ovate, with a pointed tip.
Seedling
The cotyledons are oblong, emarginated at the apex, and with 3 nerves from the base. The petiole 5mm long and the lamina 7 to 10mm long and 3mm wide. First leaves compound and opposite with 3 or 4 hispid leaflets.
- Grard P., Le Bourgeois T., Merlier H. 1996. Adventrop - Doc V.1.1. Les adventices d’Afrique soudano-sahélienne. CD-Rom, Cirad-Ca. Montpellier, France.
- Holm L. G., Plucknett D. L., Pancho J. V., Herberger J. P. 1991. The world’s worst weeds. Distribution and Biology. East-West Center by the University Press. Hawaii.
- Harada J. and Association for international cooperation of agriculture & forestry. 1996. Weeds in the tropics. Association for international cooperation of agriculture & forestry, Japan. 304p.
- Nayyar M. M., Ashiq M. and Ahmad J. 2001. Manual on Punjab weeds (Part II). Directorate of Agronomy. Ayub Agricultural Research Institute, Faisalabad Pakistan.
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