It is a widespread and very tolerant species that is found growing in a variety of habitats. 

Scientific Classification

• Kingdom: Plantae
• Phylum: Tracheophyta
• Class: Magnoliopsida
• Order: Poales
• Family: Poaceae
• Genus: Paspalum
• Species: Paspalum conjugatum
• Common Names: Buffalo grass, carabao grass, sour grass, sour paspalum, hilo grass, yellow grass, T grass.

Nativity and Distribution

Its native range is tropical and subtropical America. Its distribution is Africa, Temperate Asia, Tropical Asia, Australasia, the Pacific, North America, and South America.

It is a weed of many crops in the tropics and warm temperate zones of Asia, the Americas, Africa, and the Pacific. It is also a weed of humid pastures and open areas of conservation lands.

Physical Appearance

• Leaves: Generally short and broad with a distinct midrib and two indefinite lateral veins.
• Flowers: The spikelets are 1.5 -2cm long ovate and flattened.
• Fruit: Fruits about 1.5 x 1 mm they are flattened with fimbriate margins.
• Seeds: They are round small tiny seeds on two racemes.
• Roots: Fibrous root system.

It has many runners on the soil surface, and the stems are often purplish.

The leaf blades are 11-18 x 1-1.2 cm. They are mainly glabrous with the exception of a few hairs along the margin, the main vein is prominent on the abaxial surface.

The leaf sheath which is 3-4 cm long is hairy at the top and parchment-like further down.

The inflorescence usually comprises two-second spikes, each about 60-100 mm long. There are glands at the base of the raceme, which are well-developed and very hairy.

The spikelets are solitary pedicellates 0.3-0.5 mm long and are two rows behind the rachis.  

Life Cycle/Reproduction/Dispersal

• Life Cycle: Perennial.
• Seeds: Reproduction is by seeds.
• Climate: It is best adapted to humid climates.
• Dispersal: Small seeds are probably distributed by man and animals on clothing and fur; stolons also spread them.

It does not reproduce only by seeds; it is a morphologically stable species, which may result in a high dependence on vegetative reproduction. 

The plant prefers wet roadsides or ditches and quickly spreads via highly productive stolons. It is highly productive under good circumstances.

Environmental Impact

• A serious weed of orchards, sugarcane, vineyards, golf courses, and lawns.
• May invade forest clearings and may impede forest regeneration.
• The stoloniferous plants trail in irrigation channels and reduce water flow.
• It stifles herbs and tree seedlings.
• Inedible to cattle.
• Not good as a fodder suitable for grazing only when young.

Uses

• It may assist in the control of Imperata cylindrica if the pasture is heavily grazed.
• It is used as fresh grass in pastures and cut and carry systems.
• It is suitable as a lawn grass because it withstands mowing and footwear.

Control

It can be displaced in pastures by towering forage grasses. It cannot be controlled by mulching due to strong stoloniferous growth.

Apparently, it is not suppressed by slashing, as slashing encourages the plant’s growth. It can be controlled by nitrogen suppression in pastures. 

In sufficiently humid situations, legume cover crops are the main means of control in oil palm, rubber, etc. Some legumes may shade the weed and also have an allelopathic effect.

Chemical Control

When growing as a weed in crops and pastures, herbicides such as DSMA, MSMA, bromacil, dicamba, metsulfuron, paraquat, imazapyr, amitrole, and glyphosate have been used to control it. 

It should be noted that it reacts to glyphosate and imazapyr, which are both nonselective herbicides, the latter having some residual soil activity. 

Biological Control

Natural enemies are considered, but at present, there are no satisfactory biological control agents.

Sylvia Kiragu

Lead Editor for Insight Weeds.

insightweeds.com/

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