Johnson Grass

Johnson grass: see sorghum.

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Johnson Grass 

(Sorghum halepense), a perennial herbaceous plant of the Gramineae family; a pernicious weed.

The stems of Johnson grass are 1–2 m high. The inflorescence is a panicle (to 40 cm). There are two or three uniflor-ous spikes on each sprig. A single plant yields several thousand fruits, which drop off and heavily litter the soil. The rhizomes are segmented, with thick internodes and nodes. The mature plant is a vigorous bush with numerous shoots and rhizomes that densely penetrate the topsoil. The principal mass of rhizomes lies up to 20 cm deep, but a few penetrate to a depth of 60–80 cm. Johnson grass is found from the Mediterranean to India and China. In the USSR it is found in the Crimea, the Caucasus, and Middle Asia. The shoots yield a high quantity of nutritive green matter. Johnson grass is readily eaten by horned cattle and horses, both in green form and in the form of hay. At the same time, it is a dangerous and resistant weed of irrigated agriculture; it contaminates all crops, especially cotton. It often grows along the banks of rivers and irrigation ditches. Control measures include deep clod plowing in summer, drying the rhizomes for two weeks; careful and deep cultivation of row crops; sowing alfalfa and mowing it down early (which greatly suppresses and destroys the Johnson grass); autumn plowing to a depth of 20–30 cm; and systematic mowing of Johnson grass in irrigation ditches.

REFERENCES

Agadzhanian, G. Kh. Biologiia gumaia i mery bor’by s nim.Yerevan, 1939.
Kormovye rasleniia senokosov i pastbishch SSSR,vol. 1. Edited by I. V. Larin. Moscow-Leningrad, 1950.
Nikitin, V. V. Sornaia rastitet’nost’ Turkmenii.Ashkhabad. 1957.
Kott, S. A. Sornye rasteniia i bor’ba s nimi,3rd ed. Moscow, 1961.

T. V. EGOROVA and V. V. NIKITIN