Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-30T20:00:30.682Z Has data issue: false hasContentIssue false

Factors Affecting Germination of Coolatai Grass (Hyparrhenia hirta)

Published online by Cambridge University Press:  20 January 2017

Vinod K. Chejara*
Affiliation:
School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
Paul Kristiansen
Affiliation:
School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
Ralph D. B. Whalley
Affiliation:
School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
Brian M. Sindel
Affiliation:
School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia
Christopher Nadolny
Affiliation:
Department of Environment and Climate Change, P.O. Box U245, Armidale, NSW 2351, Australia
*
Corresponding author's E-mail: [email protected]

Abstract

Coolatai grass is an invasive, perennial grass from Africa and the Middle East that has infested large areas of northern New South Wales, Australia, and also occurs in other Australian states. An understanding of the seed germination ecology of Coolatai grass can assist in predicting its potential distribution and developing effective management strategies. The effects of various environmental factors on Coolatai grass seed germination were investigated in a series of laboratory experiments. The effect of diurnal alternating temperatures (5–45 C) with a 12-h photoperiod were examined on a thermogradient plate. Seed germination occurred at almost all temperature combinations from 5 to 45 C. At moderate temperatures the speed of seed germination was very high; at 30/20 C more than 80% of seeds were germinated within 12 h. Germination was slightly enhanced by the presence of light, but length of photoperiod did not affect germination. Germination at neutral pH was over 90%, and declined to 65% at acidic (pH 4) and alkaline (pH 10) pH levels. Germination was completely inhibited at an osmotic stress of −0.55 MPa or greater and was reduced by 50% at −0.37 MPa. Greater germination in relatively dry soil conditions compared with native species may contribute to the establishment of this species in the field. Results indicate that Coolatai grass seeds can germinate over a wide range of diurnal temperatures, light regimes, pH levels, and under marginal water stress. These characteristics help explain the successful invasion of Coolatai grass and provide evidence that this species is capable of establishing in many parts of Australia.

Type
Weed Biology and Ecology
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Andrews, T. S., Jones, C. E., and Whalley, R. D. B. 1997. Factors affecting the germination of Giant Parramatta grass. Aust. J. Exp. Agric. 37:439446.CrossRefGoogle Scholar
Arnon, D. I. and Johnson, C. M. 1942. Influence of hydrogen ion concentrations on the growth of higher plants under controlled conditions. Plant Physiol. 17:525539.CrossRefGoogle ScholarPubMed
Baruch, Z. and Bilbao, B. 1999. Effects of fire and defoliation on the life history of native and invader C4 grasses in a Neotropical savanna. Oecologia. 119:510520.CrossRefGoogle Scholar
Baskin, C. C., Baskin, J. M., and Cheplick, G. P. 1998. Ecology of seed dormancy and germination in grasses. Pages 3083. in. Population Biology of Grasses. Cambridge, UK Cambridge University Press.CrossRefGoogle Scholar
Bewley, J. D. and Black, M. 1994. Seeds. in. Physiology of Development and Germination. New York Plenum. 445.CrossRefGoogle Scholar
Burke, I. C., Thomas, W. E., Spears, J. F., and Wilcut, J. W. 2003. Influence of environmental factors on broadleaf signalgrass (Brachiaria platyphylla) germination. Weed Sci. 51:683689.CrossRefGoogle Scholar
Chachalis, D. and Reddy, K. N. 2000. Factors affecting Campsis radicans seed germination and seedling emergence. Weed Sci. 48:212216.CrossRefGoogle Scholar
Chauhan, B. S., Gill, G., and Preston, C. 2006. Influence of environmental factors on seed germination and seedling emergence of rigid ryegrass (Lolium rigidum). Weed Sci. 54:10041012.CrossRefGoogle Scholar
Clayton, W. D. 1969. A revision of the genus Hyparrhenia . Kew Bull. 2:1196.Google Scholar
Forcella, F., Benech-Arnold, R. L., Sanchez, R., and Ghersa, C. M. 2000. Modeling seedling emergence. Field Crops Res. 67:123139.CrossRefGoogle Scholar
Gramshaw, D. and Stern, W. 1977. Survival of annual ryegrass (Lolium rigidum Gaud.) seed in a Mediterranean type environment, II: effects of short-term burial on persistence of viable seed. Aust. J. Agric. Res. 28:93101.CrossRefGoogle Scholar
Humphries, A. W. 1965. Hyparrhenia hirta (L.) Stapf—a novel pasture species for a mediterranean type environment. CSIRO Aust. Plant Introd. Rev. 2:1718.Google Scholar
Hunt, S. 2006. Utilisation of pastures dominated by Coolatai grass (Hyparrhenia hirta). Pages 3642. in Bonnington, D. Native Grasses Association Inc. Dubbo, NSW, Australia.Google Scholar
Koger, C. H., Reddy, K. N., and Poston, D. H. 2004. Factors affecting seed germination, seedling emergence, and survival of texaweed (Caperonia palustris). Weed Sci. 52:989995.CrossRefGoogle Scholar
Kriticos, D. J., Sutherst, R. W., Brown, J. R., Adkins, S. W., and Maywald, G. F. 2003. Climate change and the potential distribution of an invasive alien plant: Acacia nilotica spp. indica in Australia. J. Appl. Ecol. 40:111124.CrossRefGoogle Scholar
Larsen, A. L. 1971. Two-way thermogradient plate for seed germination research: construction plans and procedures. Washington United States Department of Agriculture.Google Scholar
Leist, N. and Kramer, S. 2003. ISTA Working Sheets on Tetrazolium Testing. 1st ed., Volume 1. Bassersdorf, Switzerland Agricultural, Vegetable and Horticultural Species, ISTA. 176.Google Scholar
Lodge, G. M. 1981. The establishment of warm- and cool-season native perennial grasses on the north-west slopes of New South Wales. I. Dormancy and germination. Aust. J. Bot. 29:121133.CrossRefGoogle Scholar
Maze, K. M., Koen, T. B., and Watt, L. A. 1993. Factors influencing the germination of six perennial grasses of central New South Wales. Aust. J. Bot. 41:7990.CrossRefGoogle Scholar
McArdle, S. L., Nadolny, C., and Sindel, B. M. 2004. Invasion of native vegetation by Coolatai grass Hyparrhenia hirta: impacts on native vegetation and management implications. Pac. Conserv. Biol. 10:4956.CrossRefGoogle Scholar
McCormick, L. H., McMillan, M. G., and Lodge, G. M. 1992. Coolatai grass (Hyparrhenia hirta) control. Aust. Weeds Res. Newsl. 41:3638.Google Scholar
McWilliam, J. R., Shanker, K., and Knox, R. B. 1970. Effects of temperature and photoperiod on growth and reproductive development in Hyparrhenia hirta . Aust. J. Agric. Res. 21:557569.CrossRefGoogle Scholar
Michel, B. E. 1983. Evaluation of the water potentials of solutions of polyethylene glycol 8000 both in the absence and presence of other solutes. Plant Physiol. 72:6670.CrossRefGoogle ScholarPubMed
Miller, R. W. and Donahue, R. L. 2004. Soil water properties. Pages 6297. in. Soils in Our Environment. Upper Saddle River, New Jersey Prentice Hall.Google Scholar
Nadolny, C. 1998. Towards integrating farming and conservation: the role of native pastures. Pac. Conserv, Biol. 4:7078.CrossRefGoogle Scholar
[NLWRA] National Land and Water Resources Audit 2001. Australian Agriculture Assessment 2001. Braddon, Australia National Land and Water Resources Audit.Google Scholar
R Development Core Team 2006. R: A Language and Environment for Statistical Computing. Vienna R Foundation for Statistical Computing.Google Scholar
Roundy, B. A. and Biedenbender, S. H. 1996. Germination of warm-season grasses under constant and dynamic temperatures. J. Range Manage. 49:425431.CrossRefGoogle Scholar
Slattery, W. J., Conyers, M. K., Aitken, R. L., Peverill, K. I., Sparrow, L. A., and Reuter, D. J. 2001. Soil pH, aluminium, manganese and lime requirement. Pages 103108. in. Soil Analysis: An Interpretation Manual. Collingwood, Australia CSIRO Publishing.Google Scholar
Stubbendieck, J. 1974. Effect of pH on germination of three grass species. J. Range Manage. 27:7879.CrossRefGoogle Scholar
Watt, L. A. 1982. Germination characteristics of several grass species as affected by limiting water potentials imposed through a cracking clay soil. Aust. J. Agric. Res. 33:223231.CrossRefGoogle Scholar