Latin name

Panicum repens L.

Family

Poaceae

Common name(s)

Torpedo grass

Synonym(s)

Panicum gouinii E. Fourn., P. littorale Mohr. ex Vasey, P. convolutum P. Beauv. ex Spreng., P. arenarium Brot.

Geographical distribution

Asia: China (including Hong Kong and Taiwan).

South and Southeast Asia: Bangladesh, Brunei, Cambodia, India, Indonesia, Lao PDR, Malaysia, Nepal, Philippines, Sri Lanka, Thailand, and Vietnam.

Rest of the world: Arabian Peninsula, Argentina, Australia, Cuba, Dominican Republic, France, Iraq, Israel, Morocco, Portugal, Puerto Rico, South Africa, Sudan, United States, and West Africa.

Morphology

A strong perennial grass, ascending, somewhat wiry, 40—100—cm—tall .

Stem: erect or reclining, rooting at base; deep rhizomes, white with irregularly thickened parts, branching with new culms arising.

Leaf: linear and lance-shaped, up to 25—cm—long, stiff and ascending; short ligule, membranous, up to 0.5—mm—long.

Inflorescence: open panicle, 7—18—cm—long, smooth and with ascending branches; spikelets oblong-ovate, 3—mm—long.

Biology and ecology

Panicum repens thrives in wet open grasslands and field margins, and in drains of lowland rice fields; able to withstand temporary flooding. Propagates by seeds and by division of its roots and rhizomes.

Management

Cultural control: repeated cutting or by deep plowing to cut the rhizomes and bury them to 30 cm.

Chemical control: Glyphosate.

Selected references

Chandrasena JPNR. 1990. Torpedograss (Panicum repens L.) control with lower rates of glyphosate. Trop. Pest Manage. 36(4):336-342.

Chandrasena JPNR, Dhammika WHY. 1988. Studies on the biology of Panicum repens L.: comparative morphological development of three selections from different geographical localities in Sri Lanka. Trop. Pest. Manage. 34(3):291-297.

Holm L, Pancho JV, Herberger JP, Plucknett DL. 1979. A geographical atlas of world weeds. New York (USA): John Wiley & Sons, Inc. 391 p.

Hossain MA, Ishimine Y, Murayama S, Uddin SMM, Kuniyoshi K. 1999. Effect of burial depth on emergence of Panicum repens. Weed Sci. 47:651-656.

Manipura WB, Somaratne A. 1974. Some effects of manual and chemical defoliation on the growth and carbohydrate reserves of Panicum repens (L.) Beauv. Weed Res. 14:167-172.

Moody K. 1989. Weeds reported in rice in South and Southeast Asia. Manila (Philippines): International Rice Reseach Institute. 442 p.

Moody K. 1992. Weeds of cropped areas in the Philippines. Philipp. J. Weed Sci. 19:31-78.

Pancho JV, Obien SR. 1995. Manual of ricefield weeds in the Philippines. Muñoz, Nueva Ecija (Philippines): Philippine Rice Research Institute. 543 p.

Soerjani M, Kostermans AJGH, Tjitrosoepomo G. 1987. Weeds of rice in Indonesia. Jakarta (Indonesia): Balai Pustaka. 716 p.

Contributors

JLA Catindig, RT Lubigan, and DE Johnson