A study conducted at the University of Queensland suggested that 22–25 plants m -2 of C. The widespread occurrence of this species has been observed in an area of 118,000 ha of Australian agricultural land and is responsible for a substantial amount of yield and revenue loss equalling 39,300 tons of grain and AUD 7.7 million per annum, respectively.
This species is greatly distributed across the mainland of Australia and is considered as a major weed species of South Australian vineyards, grain cropping regions of Queensland, Western Australia, and Northern Territory, and cotton-growing regions of New South Wales. It is recognized as an emerging and problematic cropping weed species in Australian farming systems. virgata seeds in sticking to agricultural machinery and labors, thus reducing the energy required for dispersal.Ĭhloris virgata is known to have originated from the warm regions of the world however, the exact origin of this species is yet to be identified and is open for international debate. The two protruded trichomes could also help C. virgata prefer two kinds of dispersal methods: hydrochory and anemochory (dispersal through water and wind, respectively). virgata can travel up to 13 m in normal wind velocity. An earlier study suggested that the seeds of C. These morphological structures aid seeds in dispersal from one ecosystem to another and increase C. virgata are comparatively smaller than other weed species, aerodynamic in shape, lightweight, and exhibit two protruded trichomes (hairs). Ĭhloris virgata can produce more than 40,000 seeds plant -1 and is therefore considered a prolific seed producer. It can reach more than 1 m height, produce 600 g m -2 dry matter under suitable (summer) weather conditions, and has been classified as a host for aphids, barley yellow dwarf and cereal yellow dwarf virus, and some species of nematodes. It possesses a C 4 photosynthesis mechanism, monocotyledon seed structure, and is commonly referred to by many names depending on the region, such as Feathertop Rhodes grass in Australia feathered finger grass, feathered windmill grass, and feathered Chloris in the United States and oldland grass and sweetgrass in south-east Asia. is a summer annual species of Poaceae family that is considered a troublesome weed species across the tropics of the world. Knowledge gained from this study will help in developing site-specific and multi-tactic weed control protocols.Ĭhloris virgata Sw. The GR population SGW2 exhibited a distinctive pattern in T10, T50, and T90, possessing delayed germination behaviour and thus demonstrating an escape mechanism against pre-plating weed management practices.
Three biological parameters (T10: incubation period required to reach 10% germination T50: incubation period required to reach 50% germination and T90: incubation period required to reach 90% germination) suggested late water imbibition with increasing moisture stress levels. virgata to germinate in arid regions and drought conditions. Seed germination of all populations was inhibited at -0.8 and -1.6 MPa osmotic potential at two alternating temperature regimes (15/5 and 35/25☌) however, some seeds germinated at 25/15☌ at -0.8 MPa osmotic potential, indicating the ability of C. virgata to germinate in winter months despite being a summer annual. All populations exhibited considerable germination at the lowest alternating temperature regime 15/5☌ (61%, 87%, 49%, and 47% for Ch, SGM2, SGW2, and CP2, respectively), demonstrating the ability of C. Seeds germinated in all the temperature regimes with no clear indication of optimum thermal conditions for the GR and GS populations. These temperature regimes represent temperatures occurring throughout the year in the eastern grain region of Australia. A study was conducted using two glyphosate-resistant (GR) (SGW2 and CP2) and two glyphosate-susceptible (GS) (Ch and SGM2) populations of Chloris virgata, an emerging and troublesome weed species of Australian farming systems, to evaluate their germination response to different alternating temperature (15/5, 25/15 and 35/25☌ with 12 h/12 h light/dark photoperiod) and moisture stress regimes (0, -0.1, -0.2, -0.4, -0.8 and -1.6 MPa). Thorough knowledge of the germination behavior of weed species could aid in the development of effective weed control practices, especially when glyphosate resistance is involved.
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