Cuscuta campestris Yunck. - Field Dodder
Systematic position.Family Cuscutaceae, genus Cuscuta L.
Biological group.It is an annual stem parasitic plant.
Morphology and biology.Dodder has no normal roots and leaves. The stems of C. campestris entwine themselves around host-plants, attached by gaustoria. Stems are thread-like, yellow or pinkish-yellow, to 0.8 mm in diameter, branchy. Flowers are white or greenish, aggregated in groups of 3-8 in spreading inflorescences. Corolla is 2-2.5 mm long, bell-shaped. Calyx is 1.5-2 mm long, hemispherical. Fruit is a light-brown, 2-4-seeded boll. Seeds are oval, light-brown or brownish, to 1.25-2.5 mm long, 1-1.5 mm wide. The seeds germinate under relatively high temperatures (In nine days at +13 to 14°C, in 3 days at +20 to 30°C). Mass of 1000 seeds is 1-1.25 g. The seeds do not lose their germinating capacity in the soil for a period of 3 years. Passing through the digestive system of animals, they do not lose their germinating capacity and keep their vitality for 10 years. Productivity can reach 100,000 seeds. Flowering occurs in July and August.
Distribution.Distributed in the European part of Russia and other states of the former USSR; Caucasus, East Siberia, Far East, Middle Asia. Its native land is North America. It was documented for the first time in Russia in 1913.
Ecology.C. campestris prefers territories with abundant moisture. Immature seeds germinate faster than mature ones. The Dodder seeds are carried by wind, water, birds, other animals, and by man during the field work of machines and especially during the transportation of seed material and agricultural production containing Dodder seeds. The species is destroyed by frost in the districts that have thin snow cover in winter. Spreading speed and harmfulness of the weed depends on the density of contamination on affected crop.
Economic significance.Dodder causes a general breakdown of metabolism in cultivated plants (sucking out organic and inorganic nourishing substances), weakens and detains the growth and development of host plants, leading to their death. It parasitizes on weed and cultivated plants (jute, hemp, clover, lucerne, vetch, lens, oat, barley, dalmatic chamomile, and others), sometimes settling among wild plants. Control measures must be used before flowering. It is necessary to carefully separate the seeds of the main culture from the Dodder seeds, to destroy Dodder along road sides, boundary-strips and waste lands during the entire vegetation period. Fields affected by Dodder must be sown for 3-4 years by unsusceptible cultures.
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Beilin I.G. 1967. Control of dodders and broomrapes. Moscow: Kolos. 88 p. (In Russian)
Butov A.Ya. 1958. Some regularity in distribution of species of the genus Cuscuta L. in Middle Asia. Works of V.I. Lenin Middle-Asian State University. Botany. Tashkent: SAGU. 57-61 p. (In Russian)
Fisyunov A.V., ed. 1984. Weed control reference book. Moscow: Kolos. 254 p. (In Russian)
Nikitin V.V. 1983. Weeds in the flora of the USSR. Leningrad: Nauka. 454 p. (In Russian)
Pilyugin N. 1953. Dodder and its control. Yaroslavl: Kolhoz i sovkhoz literature. 19 p. (In Russian)
Shatalov T.A. 1987. Weed plants and their control in Rostov Region. Persianovka. 102 p. (In Russian)
Shishkin, B.K., ed. 1953. Flora of the USSR. V. 19. Moscow-Leningrad: AN SSSR. 752 p. (In Russian)
Ulyanova T.N. 1998. Weeds in the flora of Russia and other CIS states. St. Petersburg: VIR. 344 p. (In Russian)