Weeds

Sorghum halepense (L.) Pers. - Johnson Grass (Aleppo-grass, Guinea-grass)

Systematic position.

Family Poaceae, genus Sorghum Moench.

Synonym.

Andropogon halepensis (L.) Brot.

Biological group.

Perennial rhizomatous weed.

Morphology and biology.

Plant 50-200 cm high; culms erect, glabrous; nodes slightly haired. Leaf blades linear-lanceolate, 1-1.5 cm in width, glabrous, with light middle rib, dentate at margin; leaf sheath smooth; ligule to 5 mm long, green-whitish. Inflorescence paniculate, oblong, 40 cm in length; fertile spikelets sessile, haired; neuter spikelets short-pedunculate, sparsely haired. There are 3 glumes; two lower glumes coriaceous, third one membraneous. Lemmas membraneous; lower one usually having awn to 2 cm long, rarely without awn; palea small, ciliated. Blossoms in June-August.

Distribution.

Atlantic and Middle Europe, Mediterranean area, Asia Minor, Iran, Japan, China, North America, South America, Africa, South Asia, Australia (adventive plant). The South of the European part of the former USSR, Crimea, the Caucasus, Central Asia.

Ecology.

The plant is heat-loving and water-resistant, tolerant to the soil, but better growing on the nutrient-rich, well-aerated soil. Optimum temperature of germination is 28-32°C.

Economic significance.

Pernicious weed of cotton, infesting grass sorghum, corn and other tilled crops; occurring in vineyards, tobacco- and tea-plantations, orchards, along roads, irrigation canals. Control measures include early under-winter plowing, deep presowing and interrrow soil cultivation, fallow land, suppressive crops (alfalfa, vetch, winter wheat), chemical weeding, eradication before seed ripening in waste lands.

Reference citations:

Anon. 1996. Weeds on sugar beet. Berlin: Hoehst Shering AgrEvo Gmbh., 479 p. (in Russian).
Keller, B.A., ed. 1934. Weed plants of the USSR. V. 1. Leningrad: AN SSSR. 324 p. (in Russian).
Nikitin, V.V. 1983. Weed plants of the USSR flora. Leningrad: Nauka, 454 p. (in Russian).
Rozhevits, R.Ju., Shishkin, B.K., eds. 1934. Flora of the USSR. V. 2. Leningrad: AN SSSR, 778 p. (in Russian).
Ulyanova, T.N. 1998. Weed plants in the flora of Russia and other CIS states. St.-Petersburg: VIR, 344 p. (in Russian).

© Sokolova T.D.

The image of Sorghum halepense is taken from the book of Melnichuk, O.S. & Kovalivska, G.M. (1972). "Atlas of the most widespread weeds of the Ukraine" (Kiev: Urozhai, 204 p.). There is no copyright to either the whole book or the pictures themselves.