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Graminae
Synonyms
D. adscendens (H.B.K.) Henr.; D. marginata Link; D. sanguinalis
(L ) Scop.
Common names
Summer grass (Australia), pasto colchón, pate de gallo,
gramilla (Peru), pate de gallina (Cuba), hairy crabgrass (Oklahoma), wild
crabgrass (Hawaii).
Description
An annual, caespitose with branching culms; nodes pilose; leaves
linear, acuminate, the sheaths pilose; ligule elongate, obtuse, glabrous;
up to ten racemes on a triquetrous rachis; spikelets unilateral, geminate,
one sessile, one pedicelled, ovate; lower glume small, upper three-nerved,
pilose-ciliate; sterile lemma as long as the upper glume, three-nerved,
margin ciliate; fertile lemma as long as the sterile lemmas, glabrous (Henty,
1969).
Distribution
A widely distributed tropical weed.
Altitude range
Sea-level to 1 800 m.
Tolerance to herbicides
Cultivation will usually kill the grass. If a herbicide is
needed, a pre-emergence spray with diuron at 6 g of an 800 g AI/kg product
(e.g. Karmex) per litre of water plus 6 ml surfactant. Apply with a mister
till solution runs off the leaves (Tilley, 1977). It can be treated with
PCP either as a pre- emergence spray or when the seedlings are young. Oil
emulsions fortified with PCP will kill or reduce the vitality of older
plants (Kleinschmidt & Johnson, 1977).
Dry-matter and green-matter
yields
In Oklahoma United States, Dalrymple (1978) obtained yields
of 9 520-11 760 kg DM/ha and 2 240-3 360 kg DM/ha when double-cropped behind
small grains.
Main attributes
It grows on poor soils and gives some useful forage in this
situation.
Main deficiencies
It is a vigorous, stoloniferous, weedy species invading crops
and pastures, especially on sandy soils.
Palatability
It is quite palatable.
Natural habitat
Sandy soils and loams, as a weed in cultivation.
Genetics and reproduction
2n=54 (Fedorov, 1974).
Economics
A common weed of cultivated and waste or disturbed land, particularly
on sandy soils. Germination is stimulated by exposure to light. In subtropical
and dry tropical environments it affects the quality of S. humilis hay
in northern Australia and Medicago sativa (lucerne) hay in southern Australia.
In Oklahoma, United States, it is used as a forage species (Dewald, 1978).
Animal production
Average daily gains of steers on crabgrass pastures for short
periods in Oklahoma averaged 0.98 kg/day during four grazing years: 1971,
1972, 1974 and 1976 (Dewald, 1978).
Further reading
Dewald, 1978.
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