Short-term gain and long-term pain: Lessons learnt from the control of Lachnagrostis filiformis (fairy grass) in Victoria, Australia
- Authors: Warnock, Andrew , Florentine, Singarayer , Graz, Patrick , Westbrooke, Martin
- Date: 2012
- Type: Text , Journal article
- Relation: Weed Biology and Management Vol. 12, no. 4 (December 2012), p. 156-167
- Full Text: false
- Reviewed:
- Description: The indigenous Lachnagrostis filiformis colonized extensive areas of dry lake beds in Victoria, Australia, during the drought from 1997 to 2009. Large numbers of the plants' detached seed heads disperse in the wind, lodging against nearby housing, fences and other obstacles. This accumulation of material creates a fire hazard, degrades townships' aesthetics and presents a nuisance to the communities of lake-side towns. This study aimed to examine the effects of various control methods on L.?filiformis in the short and long term. Although herbicide applications, slashing, grazing and burning were found to be effective in controlling the blown L.?filiformis seed heads in the short term, they failed to prevent subsequent reinvasion and can increase its abundance in the long term. The late application of herbicide resulted in an increase in the foliage cover and seed-head biomass of L.?filiformis by up to 37% and 150%, respectively, in the year following the treatment application. The results from this study highlight how management focused on achieving short-term goals, without consideration of the successional trajectory after implementation, can not only fail but be counter-productive in the long term. In order to achieve sustainable management, the fundamental ecological processes that promote the establishment and persistence of the weed need to be addressed.
Seed germination ecology of Bidens pilosa and its implications for weed management
- Authors: Chauhan, Bhagirath , Ali, Hafiz , Florentine, Singarayer
- Date: 2019
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 9, no. 1 (2019), p.
- Full Text:
- Reviewed:
- Description: It is now widely recognized that Bidens pilosa has become a problematic broadleaf weed in many ecosystems across the world and, particularly in the light of recent climate change conditions, closer management strategies are required to curtail its impact on agricultural cropping. In this investigation, experiments were conducted to evaluate the effect of environmental factors on the germination and emergence of B. pilosa, and also on the response of this weed to commonly available post-emergence herbicides in Australia. The environmental factors of particular interest to this current work were the effect of light and temperature, salinity, burial depth and moisture on B. pilosa since these are key management issues in Australian agriculture. In addition, the effects of a number of commonly used herbicides were examined, because of concerns regarding emerging herbicide resistance. In the tested light/dark regimes, germination was found to be higher at fluctuating day/night temperatures of 25/15 °C and 30/20 °C (92–93%) than at 35/25 °C (79%), whilst across the different temperature ranges, germination was higher in the light/dark regime (79–93%) than in complete darkness (22–38%). The standard five-minute temperature pretreatment required for 50% inhibition of maximum germination was found to be 160 °C, and it was further shown that no seeds germinated at temperatures higher than 240 °C. With regard to salinity, some B. pilosa seeds germinated (3%) in 200 mM sodium chloride (NaCl) but all failed to germinate at 250 mM NaCl. Germination declined from 89% to 2% as the external osmotic potential decreased from 0 to −0.6 MPa, and germination ceased at −0.8 MPa. Seeding emergence of B. pilosa was maximum (71%) for seeds placed on the soil surface and it was found that no seedlings emerged from a depth of 8 cm or greater. A depth of 3.75 cm was required to inhibit the seeds to 50% of the maximum emergence. In this study, application of glufosinate, glyphosate and paraquat provided commercially acceptable control levels (generally accepted as >90%) when applied at the four-leaf stage of B. pilosa. However, none of the herbicide treatments involved in this study provided this level of control when applied at the six-leaf stage. In summary, B. pilosa germination has been clearly shown to be stimulated by light and thus its emergence was greatest from the soil surface. This suggests that infestation from this weed will remain as a problem in no-till conservation agriculture systems, the use of which is increasing now throughout the world. It is intended that information generated from this study be used to develop more effective integrated management programs for B. pilosa and similar weeds in commercial agricultural environments which are tending toward conservation approaches. © 2019, The Author(s).
Germination biology of four climatically varied populations of the invasive species African lovegrass (Eragrostis curvula)
- Authors: Roberts, Jason , Florentine, Singarayer , Van Etten, Eddie , Turville, Christopher
- Date: 2021
- Type: Text , Journal article
- Relation: Weed Science Vol. 69, no. 2 (2021), p. 210-218
- Full Text: false
- Reviewed:
- Description: African lovegrass [Eragrostis curvula (Schrad.) Nees] is a highly invasive C4 perennial grass that threatens global biodiversity. Appropriate management of this species has been hampered by a lack of knowledge concerning its seed ecology, resulting in significant economic and environmental impacts within various environments. Consequently, this study explored the effects of a selection of environmental factors (photoperiod, alternating temperature, pH, and salinity) by analyzing several measures of germination on four geographically distinct populations of E. curvula to assist in its extirpation from infested sites. Seeds were collected in Australia from Maffra and Shepparton, VIC; Tenterfield, NSW; and Midvale, WA. Key results showed that seeds from Maffra (54% vs. 79%), Tenterfield (38% vs. 61%), and Shepparton (34% vs. 71%) had significantly reduced germination in complete darkness compared with an alternating 12-h light and 12-h dark photoperiod, whereas Midvale had consistent germination (91% vs. 99%). Temperatures between 17/7 C reduced germination for Maffra (42% vs. 73%), Tenterfield (34% vs. 55%), and Shepparton (33% vs. 59%) compared with the mean of all other temperature combinations, whereas Midvale had consistent germination. Furthermore, germination for all populations was consistent between pH 4 and 9. For salinity, germination was significantly reduced at ≥100 mM for Maffra (29% vs. 67%), ≥150 mM for Tenterfield (29% vs. 94%) and Shepparton (39.5% vs. 81.5%), and 250 mM for Midvale (39% vs. 82%) compared with the mean of all other concentrations. Although each trial was conducted independently, the data can be used to generate species-targeted management. Such strategies include maintaining high levels of quarantine and hygiene programs to avoid future spread; where practical, applying light-limiting strategies (mulching, tilling, or scraping) for the Maffra, Tenterfield, and Shepparton populations; and maintaining management efforts year-round, as the species can germinate under a wide range of conditions. © The Author(s), 2021. Published by Cambridge University Press on behalf of the Weed Science Society of America.
A global review of the woody invasive alien species mimosa pigra (giant sensitive plant): Its biology and management implications
- Authors: Welgama, Amali , Florentine, Singarayer , Roberts, Jason
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 18 (2022), p. 2366
- Full Text:
- Reviewed:
- Description: Populations of invasive alien plants create disruptive plant communities that are extremely adaptable, imposing severe ecological impacts on agriculture, biodiversity and human activities. To minimise these impacts, prevention and effective weed management strategies are urgently required, including the identification of satellite populations before they invade new areas. This is a critical element that allows weed management practices to become both successful and cost-effective. Mimosa pigra L. (Giant sensitive plant) is an invasive weed that has spread across various environments around the world and is considered one of the world’s top 100 most invasive plant species. Being adaptable to a wide range of soil types, in addition to its woody protective prickles and low palatability, M. pigra has quickly spread and established itself in a range of habitats. Current control methods of this species include biological, chemical and physical methods, together with attempts of integrated application. Reports suggest that integrated management appears to be the most effective means of controlling M. pigra since the use of any single method has not yet proved suitable. In this regard, this review synthesises and explores the available global literature and current research gaps relating to the biology, distribution, impacts and management of M. pigra. The contribution of this work will help guide land managers to design appropriate and sustainable management programs to control M. pigra.
Biology, distribution and control of the invasive species Ulex europaeus (Gorse) : a global synthesis of current and future management challenges and research gaps
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 61, no. 4 (2021), p. 272-281
- Full Text: false
- Reviewed:
- Description: Ulex europaeus (Gorse) is one of the most invasive shrubs in the world, being now found in more than 50 countries where it economically and environmentally degrades the land. This highly versatile shrub can live more than 30 years and produce over 18,000 fertile seeds annually that can remain viable for over 30 years. Ulex europaeus spread is facilitated by its ability to germinate in a wide range of conditions, quick growth and maturing rate and several seed dispersal mechanisms. Despite extensive research and attempts at managing U. europaeus, current rates of control are not adequate to limit the species’ competitiveness and impact on the environment. This has resulted in the species altering soil and landscape dynamics in areas of major invasion, inhibiting the growth of agricultural and native species, creating shelter for pest species and reducing the richness of competing species at a site, all of which contribute to the economic and environmental degradation of the land. This review highlights that herbicide application is the most successful technique used to control U. europaeus, although it has shown varying success across different climatic regions. In this regard, future research should investigate the possibility of integrating a range of techniques (competition, fire management, grazing, manual removal and mycoherbicides) to increase control success and reduce any potential risk of herbicide resistance. Further research is also required on the maintenance of longer-term viable populations of biological control agents to limit the success of this invasive species. Bridging the identified research gaps will help to facilitate the improved long-term management of U. europaeus and help land managers confidently to maintain sustainable land systems. © 2021 European Weed Research Society
Impacts of climate change on weeds, insect pests, plant diseases and crop yields: Synthesis
- Authors: Jabran, Khawar , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2020
- Type: Text , Book chapter
- Relation: Crop protection under changing climate 6 p. 189-195
- Full Text: false
- Reviewed:
- Description: Three distinct components of climate change in the recent times are warming of the earth, increased levels of carbon dioxide in the atmosphere and erratic changes in water availability to plants. These changes in the global climate not only impact the growth and life cycles of plants but also affect their pests. Recent research demonstrates that the effects of climate change on pests, pesticides (their efficacy and post-application chemistry) and pest management are complex. This is important to document changes in the behaviour of pests and pesticides in the wake of climate change and propose pest management strategies accordingly. Nevertheless, non-chemical methods and integrated pest management will play an important role in sustainable pest control under climate change. Further, the effects of climate change factors on crop protection and crop production are desired to be understood in order to maintain the global food supplies and global food security.