Factors effecting the germination and emergence of a rangeland weed; European heliotrope (Heliotropium europaeum L.)
Talia Humphries A , Friedrich F. Graz A and Singarayer K. Florentine A B
+ Author Affiliations
- Author Affiliations
A Centre for Environmental Management, Faculty of Science and Technology, Federation University Australia, Mt Helen, Ballarat, PO Box 663, Vic. 3350, Australia.
B Corresponding author. Email: s.florentine@federation.edu.au
The Rangeland Journal 40(6) 583-590 https://doi.org/10.1071/RJ18048
Submitted: 24 April 2018 Accepted: 11 September 2018 Published: 24 October 2018
Abstract
European heliotrope (Heliotropium europaeum L.) is an important weed in semiarid and arid Australia, due to its toxicity to livestock and its ability to out-compete crops for water and soil nutrients. It is an ephemeral species; populations appear in high densities when conditions are favourable, but seeds remain dormant in the soil seedbank for extended periods of time. This study aimed to identify environmental factors that promoted the germination of this weed and factors that de-vitalise seeds. Seeds were collected from the Australian semiarid zone, at Nanya Research Station, New South Wales. The effects on seed germination and seedling emergence of H. europaeum of alternating temperature, photoperiod, drought, salinity, pH range, heat shock combined with smoke exposure, and burial depth were investigated. The highest germination rate was observed under the highest temperature regime, 30/20°C, under a photoperiod of 12 h light and 12 h dark. The weed germinated under moderate osmotic stress, but the highest germination occurred in the control treatment (no osmotic stress). The effect of salinity and pH on percentage germination was not significant. The effect of the heat shock and smoke treatment significantly reduced seed germination, with germination inhibited when seeds were exposed to 100°C for 3 min. Burial depth had a significant effect on seedling emergence, with a burial depth of 0.5 cm reducing the germination by ~20%. It is recommended that further research into using fire and tillage interventions for H. europaeum be explored, as these may be used to reduce the viable seedbank of this weed, allowing long-term control to be achieved.
Additional keywords: arid zone, light, pest, temperature, toxic.
References
Abdulghader, K., Nojavan, M., and Naghshbandi, N. (2008). Chemical stress induced by heliotrope (Heliotropium europaeum L.) allelochemicals and increased activity of antioxidant enzymes. Pakistan Journal of Biological Sciences 11, 915–919.| Chemical stress induced by heliotrope (Heliotropium europaeum L.) allelochemicals and increased activity of antioxidant enzymes.Crossref | GoogleScholarGoogle Scholar |
Aliloo, A. A. (2013). Evaluation of different techniques for breaking seed dormancy of Heliotropium europaeum L. (Boraginaceae). Journal of Biological and Environmental Sciences 7, 87–91.
Aliloo, A. A. (2016). Allelopathy of Heliotropium europaeum (Boraginaceae): Influence on small grain cereals. Journal of Biodiversity and Environmental Sciences 10, 71–78.
Australian Bureau of Meteorology (2017). Wentworth (Scotia Sanctuary) weather station, Number: 47105. Available at: http://www.bom.gov.au/jsp/ncc/cdio/wData/wdata?p_nccObsCode=136&p_display_type=dailyDataFile&p_stn_num=047105&p_startYear= (accessed 24 April 2018).
Australian Bureau of Meteorology (2018). Climate Classification Maps. Available at: http://www.bom.gov.au/jsp/ncc/climate_averages/climate-classifications/index.jsp (accessed 24 April 2018).
Baskin, C. C., and Baskin, J. M. (1998). ‘Seeds. Ecology, Biogeography, and Evolution of Dormancy and Germination.’ (Academic Press: San Diego, CA.)
Benvenuti, S., Dinelli, G., Bonetti, A., and Catizone, P. (2005). Germination ecology, emergence and host detection in Cuscuta campestris. Weed Research 45, 270–278.
| Germination ecology, emergence and host detection in Cuscuta campestris.Crossref | GoogleScholarGoogle Scholar |
Bull, L. B., Dick, A. T., Keast, J. C., and Edgar, G. (1956). An experimental investigation of the hepatotoxic and other effects on sheep of consumption of Heliotropium europaeum L.: heliotrope poisoning of sheep. Australian Journal of Agricultural Research 7, 281–332.
| An experimental investigation of the hepatotoxic and other effects on sheep of consumption of Heliotropium europaeum L.: heliotrope poisoning of sheep.Crossref | GoogleScholarGoogle Scholar |
Chachalis, D., and Reddy, K. N. (2000). Factors affecting Campsis radicans seed germination and seedling emergence. Weed Science 48, 212–216.
| Factors affecting Campsis radicans seed germination and seedling emergence.Crossref | GoogleScholarGoogle Scholar |
Chauhan, B. S., and Johnson, D. E. (2009). Seed germination and seedling emergence of synedrella (Synedrella nodiflora) in a tropical environment. Weed Science 57, 36–42.
| Seed germination and seedling emergence of synedrella (Synedrella nodiflora) in a tropical environment.Crossref | GoogleScholarGoogle Scholar |
Cullen, J. M., and Delfosse, E. S. (1990). Progress and prospects in biological control of weeds. In: ‘Proceedings of the Ninth Australian Weeds Conference’. (Ed. J. W. Heap.) pp. 452–476. (University of Adelaide: Adelaide.)
Dellow, J. J., Bourke, C. A., and McCaffery, A. C. (2004). ‘AGFACTS; Common Heliotrope.’ (NSW Agriculture, NSW.)
Faraway, J. J. (2006). ‘Extending the Linear Model with R.’ 1st edn. (Taylor and Francis Group, LLC: Boca Raton, FL.)
Florentine, S. K., Weller, S., Graz, F. P., Westbrooke, M. E., Florentine, A., Mansoor, J., Fernando, N., Chauhan, B. S., and Dowling, K. (2016). Influence of selected environmental factors on seed germination and seedling survival of the arid zone invasive species tobacco bush (Nicotiana glauca R. Graham). The Rangeland Journal 38, 417–425.
| Influence of selected environmental factors on seed germination and seedling survival of the arid zone invasive species tobacco bush (Nicotiana glauca R. Graham).Crossref | GoogleScholarGoogle Scholar |
Harper, J. L., and Ogden, J. (1970). The reproductive strategy of higher plants: I. The concept of strategy with special reference to Senecio vulgaris L. Journal of Ecology 58, 681–698.
| The reproductive strategy of higher plants: I. The concept of strategy with special reference to Senecio vulgaris L.Crossref | GoogleScholarGoogle Scholar |
Hill, B. D., Gaul, K. L., and Noble, J. W. (1997). Poisoning of feedlot cattle by seeds of Heliotropium europaeum. Australian Veterinary Journal 75, 360–361.
| Poisoning of feedlot cattle by seeds of Heliotropium europaeum.Crossref | GoogleScholarGoogle Scholar |
Hunt, J. R. (2005). The ecology of common heliotrope (Heliotropium europaeum L.) in a Mediterranean dry-land cropping system. PhD Thesis, Faculty of Land and Food Resources, The University of Melbourne, Australia.
Hunt, J. R., Cousens, R. D., and Knights, S. E. (2006). The germination ecology of common heliotrope (Heliotropium europaeum L.). In: ‘Managing Weeds in a Changing Climate’. (Eds C. Preston, J. H. Watts and N. D. Crossman.) pp. 126–129. (Weed Management Society of South Australia: Adelaide.)
Hunt, J. R., Cousens, R. D., and Knights, S. (2008). The biology of Australian weeds 51. Heliotropium europaeum L. Plant Protection Quarterly 23, 146–152.
Hunt, J. R., Cousens, R. D., and Knights, S. E. (2009). Heliotropium europaeum only germinates following sufficient rainfall to allow reproduction. Journal of Arid Environments 73, 602–610.
| Heliotropium europaeum only germinates following sufficient rainfall to allow reproduction.Crossref | GoogleScholarGoogle Scholar |
Köppen, W. (1900). Versuch einer Klassifikation der Klimate, Vorzugsweise nach ihren Beziehungen zur Pflanzenwelt. Geographische Zeitschrift 6, 593–611.
Mahmood, A. H., Florentine, S. K., Fernando, N., Write, W., Palmer, G., McLaren, D., and Sillitoe, J. (2016). Investigations into the effects of elevated carbon dioxide and drought on the growth and physiology of carpet weed (Galenia pubescens Eckl. and Zeyh.). In: ‘Twentieth Australian Weeds Conference’. Perth, WA. (Eds C. Preston, J. H. Watts and N. D. Crossman.) pp. 1–4. (Curran Associates, Inc.)
Martins, B. A. B., and Christoffoleti, P. J. (2015). Buttonweed emergence as affected by seed burial depth and straw on the soil surface. Scientia Agrícola 72, 489–494.
| Buttonweed emergence as affected by seed burial depth and straw on the soil surface.Crossref | GoogleScholarGoogle Scholar |
Mennan, H., Ngouajio, M., Kaya, E., and Isik, D. (2009). Weed management in organically grown kale using alternative cover cropping systems. Weed Technology 23, 81–88.
| Weed management in organically grown kale using alternative cover cropping systems.Crossref | GoogleScholarGoogle Scholar |
Mojzes, A., Csontos, P., and Kalapos, T. (2015). Is the positive response of seed germination to plant-derived smoke associated with plant traits? Acta Oecologica 65–66, 24–31.
| Is the positive response of seed germination to plant-derived smoke associated with plant traits?Crossref | GoogleScholarGoogle Scholar |
Naghipour, A. A., Bashari, H. K., Khajeddin, S., Tahmasebi, P., and Iravani, M. (2016). Effects of smoke, ash and heat shock on seed germination of seven species from Central Zagros rangelands in the semi-arid region of Iran. African Journal of Range & Forage Science 33, 67–71.
| Effects of smoke, ash and heat shock on seed germination of seven species from Central Zagros rangelands in the semi-arid region of Iran.Crossref | GoogleScholarGoogle Scholar |
R Core Team (2016). ‘R: A Language and Environment for Statistical Computing.’ (R Foundation for Statistical Computing: Vienna, Austria.)
Reinartz, J. A. (1984). Life history variation of common mullein (Verbascum thapsus): I. Latitudinal differences in population dynamics and timing of reproduction. Journal of Ecology 72, 897–912.
| Life history variation of common mullein (Verbascum thapsus): I. Latitudinal differences in population dynamics and timing of reproduction.Crossref | GoogleScholarGoogle Scholar |
Sheppard, A. W., Brun, L. A., and Lewis, R. C. (1996). A demographic comparison of common Heliotrope, Heliotropium Europaeum L.: southern Australia and southern France. In: ‘Proceedings of the 11th Australian Weeds Conference’. Melbourne, Australia, 30 September–3 October. (Ed. R. C. H. Shepherd.) pp. 286–290. (Weed Science Society of Victoria Inc.: Melbourne.)
Tieu, A., Dixion, K., Meney, K., and Sivasithamparam, K. (2001). The interaction of heat and smoke in the release of seed dormancy in seven species from southwestern Western Australia. Annals of Botany 88, 259–265.
| The interaction of heat and smoke in the release of seed dormancy in seven species from southwestern Western Australia.Crossref | GoogleScholarGoogle Scholar |
Travlos, I., and Paspatis, E. (2008). Aspects of the allelopathic effects of heliotrope (Heliotropium europaeum) on Avena sativa, Phaseolus vulgaris and Spirodela polyrhiza. Allelopathy Journal 21, 397–404.
Veiga-Barbosa, L., and Pèrez-García, F. (2016). Seed dormancy and germination of Heliotropium europaeum L. (Boraginaceae), a widespread summer-annual weed. Journal of Biodiversity and Environmental Sciences 10, 107–113.
Vidiella, P. E., and Armesto, J. J. (1989). Emergence of ephemeral plant species from soil samples of the Chilean coastal desert in response to experimental irrigation. Revista Chilena de Historia Natural 62, 99–107.
