Allelopathic effects of Eucalyptus victrix L. on Eucalyptus species and grasses
- Authors: Florentine, Singarayer , Fox, John
- Date: 2003
- Type: Text , Journal article
- Relation: Allelopathy Journal Vol. 11, no. 1 (2003), p. 77-83
- Full Text: false
- Reviewed:
- Description: C1
- Description: 2003000583
Barley (1 -> 3; 1 -> 4)-beta-glucan and arabinoxylan content are related to kernel hardness and water uptake
- Authors: Gamlath, Jayantha , Aldred, Peter , Panozzo, Joe
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Cereal Science Vol. 47, no. 2 (Mar 2008), p. 365-371
- Full Text: false
- Reviewed:
- Description: Harder kernels in barley are thought to be a factor affecting the modification of the endosperm during malting by restricting water and enzyme movement within the endosperm. The objective of this study was to investigate the relationship between kernel hardness, water uptake and the endosperm composition in barley. A range of barley samples from 2003 and 2004 crops were analyzed for kernel hardness by the Single Kernel Characterization System, water uptake during steeping and chemical composition of the endosperm including (1→3; 1→4)-
- Description: C1
New records of springtails in New Zealand pasture : How well are our pastoral invertebrates known?
- Authors: Greenslade, Penelope , Boyer, Stéphane , Wratten, Steve
- Date: 2013
- Type: Text , Journal article
- Relation: New Zealand Journal of Agricultural Research Vol. 56, no. 2 (2013), p. 93-101
- Full Text: false
- Reviewed:
- Description: Twenty-four collembolan species are recorded from improved pastures and clovers in New Zealand, of which 17 can be named to species or probable species, the others only to genus. Of the 17 named species, nine have been recorded before from New Zealand but the other eight are new records for the country. All named species are considered as introduced to New Zealand, probably originally from Europe and are unlikely to colonise native habitats. As all named species reported as new records can be abundant at times, this indicates poor knowledge of a major part of New Zealand's agricultural fauna. Collembola are a group of important microarthropod detritivores that make a significant contribution to ecosystem services. The absence so far of quantification of the contribution this and other soil groups make to ecological resilience and function is a serious problem. © 2013 The Royal Society of New Zealand.
- Description: 2003011135
Manipulating avocado fruit ripening with 1-methylcyclopropene
- Authors: Adkins, Matthew , Hofman, Peter , Stubbings, Barbara , Macnish, Andrew
- Date: 2005
- Type: Text , Journal article
- Relation: Postharvest Biology and Technology Vol. 35, no. 1 (2005), p. 33-42
- Full Text: false
- Reviewed:
- Description: Previous investigations with 1-methylcyclopropene (1-MCP) on avocado (Persea americana Mill.) fruit have focussed mainly on improving storage life by reducing the severity of disorders causing discolouration of the flesh. Development of 1-MCP and ethylene treatments, which also help control the time to reach the eating ripe stage, may confer additional practical benefits. In this context, the current study investigated the potential of 1-MCP to accurately manipulate ripening of non-stored 'Hass' avocado fruit by treatment before or after ethylene and at different times during ripening. To investigate this, 500 nL L-1 1-MCP was applied within 1 day after harvest, followed by ethylene 0-14 days after 1-MCP. In addition, fruit were treated with ethylene, then 1-MCP 0-8 days after ethylene. Treatment of fruit with 500 nL L-1 1-MCP for 18 h at 20°C provided the maximum effect by increasing the days from harvest to ripe (DTR) from 8 (with no 1-MCP) to 20. Fruit treated with 500 nL L-1 1-MCP for 18 h at 20°C remained insensitive to 100
- Description: C1
- Description: 2003001040
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.
Extending shelf-life of fresh-cut green peppers using pressurized argon treatment
- Authors: Meng, Xiangyong , Zhang, Min , Adhikari, Benu
- Date: 2012
- Type: Text , Journal article
- Relation: Postharvest Biology and Technology Vol. 71, no. (2012), p. 13-20
- Full Text: false
- Reviewed:
- Description: When fresh-cut fruit and vegetables are subjected to pressurized argon treatments, the argon gas dissolves into water and forms clathrate hydrates which ultimately lead to restriction in water mobility. In this study, fresh-cut green peppers were subjected to pressurized (2-6MPa) argon treatments for 1h. The untreated (control) and argon-treated samples were placed in polystyrene packaging with 5% O 2 and 8% CO 2 and then stored at 4°C and 90% RH for 12d. Various quality parameters of fresh-cut green peppers treated at 2, 4 and 6MPa of argon were compared with those of the control. Water loss, ascorbic acid loss, visual sensory quality, malondialdehyde (MDA), cell membrane permeability, cell protective enzyme activity and microbial quality were determined every 2d. Water mobility and loss of water in fresh-cut green peppers was greatly reduced by the pressurized argon treatment. Similarly, the loss of ascorbic acid, chlorophyll content and hue angle was also reduced during storage. The pressurized argon treatments were found to maintain the cell integrity by inhibiting an increase in MDA and membrane permeability compared to the control samples. The activities of catalase (CAT) and peroxidase (POD) were inhibited by the pressurized argon treatment. The treatment also reduced proliferation of spoilage microorganisms such as coliforms, yeasts and moulds. The fresh-cut green peppers treated by pressurized argon at 4MPa for 1h could be kept in a fresh-like condition for 12d at 4°C. © 2012 Elsevier B.V.
Liberating soil data for profitable agriculture and catchment health in the Corangamite region, Australia
- Authors: Dahlhaus, Peter , Nicholson, Cameron , Ryan, Bret , MacLeod, Andrew , Milne, Robert
- Date: 2018
- Type: Text , Journal article
- Relation: New Zealand Journal of Agricultural Research Vol. 61, no. 3 (2018), p. 333-339
- Full Text: false
- Reviewed:
- Description: Detailed soil data has been collected in the Corangamite region of south-east Australia for over 80 years, as a testament to the productive value of the region’s agricultural soils. Soil science over that period has resulted in soil maps, soil investigation sites and archival materials that provide valuable baseline data for the analysis of trends over time. This legacy data has been brought together with contemporary data in the award-winning Soil Health Knowledge Base, an Internet portal based on spatial data infrastructure that interoperably federates data (open data, research data, industry data, sensor data, legacy data, crowdsourced data … any available data). The portal provides the best available data sources for research and consulting, as well as functions for both the private reward and the public good. The ultimate intent is to provide timely decision support for agricultural enterprises and catchment managers to protect, enhance and restore soil health.
Improving the information content in soil pH maps: a case study
- Authors: Robinson, Nathan , Benke, Kurt , Norng, Sorn , Kitching, Matt , Crawford, Deborah
- Date: 2017
- Type: Text , Journal article
- Relation: European Journal of Soil Science Vol. 68, no. 5 (2017), p. 592-604
- Full Text: false
- Reviewed:
- Description: Uncertainties associated with legacy data contribute to the spatial uncertainty of predictions for soil properties such as pH. Examples of potential sources of error in maps of soil pH include temporal variation and changes in land use over time. Prediction of soil pH can be improved with a linear mixed model (LMM) to analyse factors that contribute to uncertainty. Probabilities from conditional simulations in combination with agronomic critical thresholds for acid-sensitive species can be used to identify areas that are likely, or very likely, to be below these critical thresholds for plant production. Because of rapid changes in farming systems and management practices, there is a need to be vigilant in monitoring changes in soil acidification. This is because soil acidification is an important factor in primary production and soil sustainability. In this research, legacy data from south-western Victoria (Australia) were used with model-based geostatistics to produce a map of soil pH that accommodates a variety of error sources, such as the time of sampling, seasonal variation, differences in analytical method, effects of changes in land use and variable soil sample depth in legacy data. Spatial covariates that are representative of soil-forming factors were used to improve predictions. To transform spatial prediction and estimates of error in soil pH into more informative and usable maps with more information content, simulations from the conditional distribution were used to compute the probability of a soil's pH being less than critical agronomic production thresholds at each of the prediction locations. These probabilities were mapped to reveal areas of potential risk. Highlights: Can maps of soil pH be improved by accounting for temporal variation and change in land use? First example of taking account of temporal variability in sampling for pH in spatial models. Key factors for uncertainty in spatial prediction include time of sampling and sample depth. Accuracy improved by accounting for additional sources of error combined with conditional simulations. © 2017 British Society of Soil Science
Factors affecting seed germination of feather fingergrass (Chloris virgata)
- Authors: Fernando, Nimesha , Humphries, Talia , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2016
- Type: Text , Journal article
- Relation: Weed Science Vol. 64, no. 4 (2016), p. 605-612
- Full Text: false
- Reviewed:
- Description: Laboratory experiments were carried out to determine the effect of several environmental factors on seed germination of feather fingergrass, one of the most significant emerging weeds in warm regions of the world. Seed germination occurred over a broad range of temperatures (17/7, 25/10, and 30/20 C), but germination being highest at alternating temperatures of 30/20 C under both 12 h light/12 h dark and 24 h dark conditions. Although seed germination was favored by light, some seeds were capable of germinating in the dark. Increasing salt stress decreased seed germination until complete inhibition was reached at 250-mM sodium chloride. Germination decreased from 64 to 0.7% as osmotic potential decreased from 0 to -0.4 MPa, and was completely inhibited at -0.6 MPa. Higher seed germination (>73%) was observed in the range of pH 6.4 to 8 than the other tested pH levels. Heat shock had a significant effect on seed germination. Germination of seeds placed at 130 C for 5 min was completely inhibited for both dry and presoaked seeds. The results of this study will help to develop protocols for managing feather fingergrass, and to thus avoid its establishment as a troublesome weed in economically important cropping regions.
Implications of narrow crop row spacing in managing weeds in mungbean (Vigna radiata)
- Authors: Chauhan, Bhagirath , Florentine, Singarayer , Ferguson, Connor , Chechetto, Rodolfo
- Date: 2017
- Type: Text , Journal article
- Relation: Crop Protection Vol. 95, no. (2017), p. 116-119
- Full Text: false
- Reviewed:
- Description: The mungbean production area is increasing in Australia due to increasing demand for the grain in Asian countries. However, the mungbean crop is generally grown with wide row spacing, and therefore, it is prone to heavy weed infestation which has a significant impact on the mungbean grain yield. Experiments were conducted in 2015 and 2016 to determine the row-spacing impact on crop yield and weed growth for mungbean grown in 25, 50, and 75 cm space rows. Row spacing did not affect weed biomass and mungbean grain yield when weeds were allowed to grow from crop sowing to maturity. However, narrower row spacing (25 and 50 cm) had lower weed biomass and higher grain yield when weeds were allowed to grow beyond 3 and 6 weeks after planting (WAP). Mungbean grown at 25 and 50 cm rows had 60-70% and 70-92% less weed biomass than the mungbean grown at 75 cm rows for the weeds grown beyond 3 and 6 WAP, respectively. In weed-free conditions, too, mungbean grain yields were greater in narrow rows than in wider rows. Weeds grown beyond 6 WAP did not affect grain yield of 25 and 50 cm rows but reduced mungbean yield with 75 cm rows. The practical implication of this study is that narrowing row spacing in mungbean could lead to reduced weed growth and seed production and increased crop yield. (C) 2016 Elsevier Ltd. All rights reserved.
Systemic iron implants alleviate symptoms of Mundulla Yellows in roadside eucalypts in south east South Australia
- Authors: Schultz, Nick , Good, Megan
- Date: 2018
- Type: Text , Journal article
- Relation: Australasian Plant Pathology Vol. 47, no. 4 (2018), p. 393-403
- Full Text: false
- Reviewed:
- Description: Mundulla Yellows is a dieback disorder of trees (predominantly eucalypts) along roadsides in the southeast of South Australia, characterized by interveinal yellowing of leaves and eventual death. There are two main theories about the cause of Mundulla Yellows: (1) that the yellowing is lime chlorosis, caused by crushed limestone dust from roads being washed into soil, and (2) that it is caused by an irreversible and transmissible biotic pathogen. We tested the lime chlorosis hypothesis by inserting nutrients directly into the sapwood of symptomatic trees using systemic nutrient implants. If the lime chlorosis hypothesis is correct, nutrient injections of iron and manganese should increase chlorophyll synthesis and result in leaves becoming greener. We applied four different nutrient combinations (iron, manganese, iron + manganese, and a treatment that included a range of essential plant nutrients), as well as control treatments, to symptomatic trees across 10 sites. After 14 weeks there were significant increases in leaf greenness and crown health, compared to controls, when trees received either iron or iron and manganese implants. The results add further weight to the lime chlorosis hypothesis. Nutrient implants are unlikely to be a viable management strategy due to their cost and potentially short-term benefits, and trees will inevitably be lost from the region’s roadsides. Management options should involve increasing revegetation efforts and natural passive regeneration of trees away from affected roadsides, and revegetating the affected areas with species that are suited to the changed soil conditions.
Herbicide efficacy for aquatic Alternanthera philoxeroides management in an early stage of invasion : Integrating above-ground biomass, below-ground biomass and viable stem fragmentation
- Authors: Clements, Daniel , Dugdale, Tony , Butler, Kym , Florentine, Singarayer , Sillitoe, Jim
- Date: 2017
- Type: Text , Journal article
- Relation: Weed Research Vol. 57, no. 4 (2017), p. 257-266
- Full Text: false
- Reviewed:
- Description: Alternanthera philoxeroides is a problematic invasive plant in many regions of the world that is difficult to control once naturalised. It poses a threat to agricultural productivity, biodiversity and social amenity values of aquatic environments. Significant research has been conducted internationally, regarding the efficacy of different herbicides for control of A. philoxeroides. However, no studies have looked at key aspects of control for effective management in an early stage of invasion of aquatic environments, hindering eradication and control programmes. This study evaluates the efficacy of herbicides and surfactants on key A. philoxeroides response metrics, including control of above-ground biomass, below-ground biomass and production of viable stem fragments. This study concluded that glyphosate (isopropylamine salt) minimises viable stem fragment production post-herbicide application, compared with imazapyr and metsulfuron, thus reducing the potential for dispersal throughout catchments and waterways. In contrast, imazapyr and metsulfuron provided more effective control than glyphosate for A. philoxeroides growing on exposed embankments. We propose that an effective management strategy for early invasion of aquatic A. philoxeroides, using herbicides, would be to conduct initial applications of glyphosate to control overwater biomass and limit dispersal of viable stem fragments. Once infestations have been forced back to the embankment, imazapyr or metsulfuron treatments will provide longer term control. © 2017 European Weed Research Society
Influence of various environmental factors on seed germination and seedling emergence of a noxious environmental weed: Green Galenia (Galenia pubescens)
- Authors: Mahmood, Ako , Florentine, Singarayer , Chauhan, Bhagirath , McLaren, David , Palmer, Grant , Wright, Wendy
- Date: 2016
- Type: Text , Journal article
- Relation: Weed Science Vol. 64, no. 3 (2016), p. 486-494
- Full Text: false
- Reviewed:
- Description: Green galenia is a South African woody prostrate perennial that was first recorded in Australia in the early 1900s and has since become a serious threat to indigenous temperate grasslands and surrounding agricultural areas. Laboratory and field based experiments were conducted to examine the effect of environmental factors on the germination and viability of green galenia seed. It was shown that green galenia was able to germinate over a broad range of temperatures, but short bursts (5 min) of high temperatures (80 C to 120 C replicating possible exposures to a fire) reduced seed germination. Seed germination was positively favored by light, declined rapidly in darkness, and decreased by >80% at a depth of only 0.5 cm in soil. Water stress greatly reduced seed germination (45% germination at osmotic potentials below -0.2 MPa). Germination was completely inhibited at water potentials of -0.4 to -1.0 MPa. This species is moderately tolerant to salinity, with over 50% of seeds germinating at low levels of salinity (60 mM NaCl), and moderate germination (49%) occurring at 120 mM NaCl, it can germinate well in both alkaline (pH 10-83%) and acidic (pH 4-80%) conditions. The results of this study have contributed to our understanding of the germination and emergence of green galenia, and this will assist in developing tools and strategies for the long term management of this noxious weed in Victoria and other parts of Australia. Nomenclature: Green galenia, Galenia pubescens (Eckl. & Zeyh.) Druce.
Influence of selected environmental factors on seed germination and seedling emergence of Dinebra panicea var. brachiata (Steud.)
- Authors: Weller, Sandra , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2019
- Type: Text , Journal article
- Relation: Crop Protection Vol. 117, no. (2019), p. 121-127
- Full Text: false
- Reviewed:
- Description: Dinebra panicea var. brachiata (Steud.) is related to genus Leptochloa., some species of which are significant rice crop weeds. However, little is known about how D. panicea responds to various environmental cues. This study investigates the effects of temperature, light, salt stress, moisture stress, pH, heat shock, smoke, and burial depth on seeds collected in successive years (2015 and 2016) from Queensland, Australia. Seed germination was higher overall for older seeds (2015) compared to younger (2016) at 30/20 °C and 25/15 °C, but there was less difference between light treatments (12 L/D, 24D) in both temperature ranges for older seeds compared to younger. Increasing moisture and salt stress gradually reduced germination, germination was high over the pH range from pH 4 to pH 10, short term (three minutes) heat exposure to 80 °C or less did not inhibit germination, but there was no significant difference between years for any of these environmental cues. Germination was greatly reduced at 100 °C and eliminated at 120 °C. Smoke significantly inhibited germination. Seeds from both years germinated on the soil surface and emerged from 0.2 cm, with no emergence from deeper than 0.5 cm. The data collected from this study may assist land managers to manage infestations of this weed.
Germination ecology of hairy fleabane (Conyza bonariensis) and its implications for weed management
- Authors: Loura, Deepak , Sahil , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2020
- Type: Text , Journal article
- Relation: Weed Science Vol. 68, no. 4 (Jul 2020), p. 411-417
- Full Text: false
- Reviewed:
- Description: Hairy fleabane [Conyza bonariensis(L.) Cronquist] is a problematic weed in Australian no-till cropping systems. Consequently, a study was conducted to examine the effect of temperature, light, salt stress, osmotic stress, burial depth, and sorghum crop residue on germination and emergence in two populations (C and W: collected from chick pea [Cicer arietinumL.] and wheat [Triticum aestivumL.] fields, respectively) ofC. bonariensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C); however, the C population had optimum (and similar) germination over the range of 20/10 and 30/20 C, while the W population showed maximum germination at 25/15 C. A negative relationship was observed between osmotic potential and germination, with 31% and 14% germination of the C and W populations at -0.6 MPa, respectively. These observations suggest that population C was more tolerant to higher osmotic potentials than population W. Seeds of both populations germinated when exposed to a wide range of sodium chloride levels (NaCl, 0 to 200 mM); however, beyond 200 mM NaCl, no germination was observed in either population. Maximum germination of the C (70%) and W (41%) populations was observed on the soil surface with no emergence from a burial depth of 1 cm. The application of sorghum residue at an amount of 6,000 kg ha(-1)reduced emergence of the C and W populations by 55% and 58%, respectively, compared with the no-residue treatment. Knowledge gained from this study suggests that the following strategies could be used for more efficacious management ofC. bonariensis: (1) a shallow-tillage operation to bury weed seeds in conventional tillage systems, and (2) retention of sorghum residue on the soil surface in no-till systems.
New records of springtails in New Zealand pasture: how well are our pastoral invertebrates known?
- Authors: Greenslade, Penelope , Boyer, Stéphane , Wratten , Steve
- Date: 2013
- Type: Text , Journal article
- Relation: New Zealand Journal of Agricultural Research Vol. 56, no. 2 (2013), p. 93-101
- Full Text: false
- Reviewed:
- Description: Twenty-four collembolan species are recorded from improved pastures and clovers in New Zealand, of which 17 can be named to species or probable species, the others only to genus. Of the 17 named species, nine have been recorded before from New Zealand but the other eight are new records for the country. All named species are considered as introduced to New Zealand, probably originally from Europe and are unlikely to colonise native habitats. As all named species reported as new records can be abundant at times, this indicates poor knowledge of a major part of New Zealand's agricultural fauna. Collembola are a group of important microarthropod detritivores that make a significant contribution to ecosystem services. The absence so far of quantification of the contribution this and other soil groups make to ecological resilience and function is a serious problem.
Germination biology of three populations of Navua sedge (Cyperus aromaticus)
- Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Dowling, Kim , Turville, Christopher
- Date: 2021
- Type: Text , Journal article
- Relation: Weed Science Vol. 69, no. 1 (2021), p. 69-81
- Full Text: false
- Reviewed:
- Description: Navua sedge [Cyperus aromaticus (Ridley) Mattf. & Kük.] is an aggressive perennial sedge native to equatorial Africa that has become problematic in many Pacific islands and wet, tropical Queensland, Australia. It has had a significant impact on the livestock-grazing industry, sugarcane (Saccharum officinarum L.) and banana (Musa acuminata Colla) plantations, and various other ecosystems. A laboratory-based research investigation was conducted to understand germination and emergence requirements under various environmental conditions of three geographically varied populations sourced from South Johnstone (SJ), Mackay (M) and Nyleta Creek (NC) in Queensland. Germination was identified to be stimulated by light, with no germination recorded under darkness. Populations SJ and NC had optimal germination at alternating temperatures of 25/15, 30/20, and 35/25 C, whereas population M had optimal germination at 25/15 and 30/20 C. All populations recorded greater than 85% germination at all pH levels tested. Seeds of population SJ were more sensitive to salinity compared with populations M and NC, with SJ showing no germination at 100 mM, whereas populations M and NC had 23% and 9% germination, respectively. An inverse relationship was observed between osmotic potential and germination, with no germination recorded at osmotic potentials below -0.8 MPa in any population, indicating moisture availability is a critical requirement for germination. Exposing seeds to 120 C radiant heat completely inhibited germination in populations M and NC, whereas 3% of population SJ germinated following a 180-s exposure at 120 C. Seedling emergence decreased as planting depth increased. Emergence was greatest for seeds on the soil surface or at 0.5-cm burial depth, consistent with germination being stimulated by light. Knowledge of these biological characteristics of C. aromaticus seed germination will assist in investigation of suitable control actions for this species, particularly in the early stage of its invasion into new areas, and will contribute to significant reduction in the soil seedbank. © 2021 Cambridge University Press. All rights reserved.
Seed longevity and germination in response to changing drought and heat conditions on four populations of the invasive weed 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. 4 (2021), p. 468-477
- Full Text: false
- Reviewed:
- Description: African lovegrass [Eragrostis curvula (Schrad.) Nees] is an invasive weed that is threatening biodiversity around the world and will continue to do so unless its efficient management is achieved. Consequently, laboratory and field-based experiments were performed to analyze several measures of germination to determine the effect of drought stress, radiant heat stress, and burial depth and duration (longevity) on E. curvula seeds. This study investigated seeds from four spatially varied populations across Australia: Maffra and Shepparton, VIC; Tenterfield, NSW; and Midvale, WA. Results showed that increasing drought stress reduced and slowed germination for all populations. Maffra (24% vs. 83%) and Shepparton (41% vs. 74%) were reduced at the osmotic potential of ≤-0.4 MPa, while Tenterfield (35% vs. 98.6%) and Midvale (32% vs. 91%) were reduced at ≤-0.6 MPa, compared with the mean of all other osmotic potentials. Radiant heat at 100 C significantly reduced and slowed germination compared with 40 C for Tenterfield (62% vs. 100%), Shepparton (15% vs. 89%), and Midvale (41% vs. 100%), while Maffra (75% vs. 86%) had consistent germination. For the effect of burial depth and duration (longevity), there was no significant difference across the 14-mo period; however, the 0-cm burial depth had a significantly lower final germination percentage compared with depths of 3, 5, and 10 cm (24% vs. 55%). Although each trial was conducted independently, the results can be used to help identify efficient control measures to reduce infesting populations. Recommended measures include using soil moisture monitoring to detect which conditions will promote germination, as germination is encouraged when the osmotic potential is >-0.6 MPa; exposing seeds to radiant heat (>100 C) using methods such as prescribed burning; and limiting soil disturbance over time to reduce seed establishment. © Authors 2021
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.