Emergence and survival of buried doublegee (Emex australis Steinh.) seeds

1987 ◽  
Vol 27 (1) ◽  
pp. 101 ◽  
Author(s):  
AH Cheam
Keyword(s):  
Environmental Factors ◽  
Western Australia ◽  
Inverse Relationship ◽  
Direct Relationship ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Emex Australis ◽  
Viable Seeds ◽  
The Waves

The emergence and survival of seed of doublegee (Emex australis Steinh.) buried at various depths were studied over 4 years at 3 climatically contrasting sites in Western Australia. We concluded that there is an optimal burial depth for seedling emergence and seed survival. Seeds placed at 1 cm gave maximum emergence but no seedling emerged from seeds placed at 15 cm or deeper. Emergence occurred mainly during the first autumn from seed less than 1 year old. Over the following 3 years, emergence declined progressively. The waves of emergence reflected the seasonal rainfall pattern, although emergence did not occur after every rainfall. There was no direct relationship between emergence and loss of seed viability. At the coolest site with higher rainfall the retention of viable seeds increased with increasing depth in the soil, whereas at warmer sites with lower rainfall there was an inverse relationship between viability and burial depth. The viable seeds exhumed after 4 years of burial were in different states of dormancy but induced or innately dormant seeds predominated at the cooler higher rainfall site. These types of dormancies and the various environmental factors will determine the number of viable seeds germinating in any given season. It is shown that even when the influx of new seed was stopped for 4 consecutive years, it was still not possible to achieve complete reduction in numbers of doublegee seeds.

scholarly journals Effect of Environmental Factors on the Germination and Emergence of Drunken Horse Grass (Achnatherum inebrians)

Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Yonghuan Yue ◽  
Guili Jin ◽  
Weihua Lu ◽  
Ke Gong ◽  
Wanqiang Han ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Germination Percentage ◽  
Western China ◽  
Burial Depth ◽  
Achnatherum Inebrians ◽  
Water Ph

Abstract Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH and burial depth, on the seed germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, 35°C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, 40/30°C, and the seed germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25°C, and germination was prevented at 45/35°C. Light did not appear to affect seed germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to -1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at -1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm but declined with increasing burial depth and no emergence at 9 cm. Deep tillage may be effective in limiting the seed germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention and control of this species.

scholarly journals Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
RC. XIONG ◽  
Y. MA ◽  
HW. WU ◽  
WL. JIANG ◽  
XY. MA
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Field Experiments ◽  
Cropping Systems ◽  
Control Strategies ◽  
Seedling Emergence ◽  
Central China ◽  
Burial Depth ◽  
Temperature Regimes ◽  
Alternating Temperature

ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (>90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ³ 150 mM NaCl or ³ 200 mM NaHCO3 concentrations. However, pH values from 5 to 9 had no effect on seed germination. Seedling emergence was significantly affected by burial depth and maximum emergence (78.1-85.6%) occurred at the 1-4 cm depth. The results of this study have contributed to our understanding of the germination and emergence of velvetleaf and should enhance our ability to improve control strategies in cropping systems in central China.

scholarly journals Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence

2013 ◽  
Vol 31 (2) ◽  
pp. 267-279 ◽  
Author(s):  
E. Soltani ◽  
A. Soltani ◽  
S. Galeshi ◽  
F. Ghaderi-Far ◽  
E. Zeinali
Keyword(s):  
Oilseed Rape ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Soil Seed Banks ◽  
Seed Bank Dynamics ◽  
Autumn And Winter ◽  
Lower Slope

Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03). The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.

The effect of in situ seed burial on dormancy break in three woody-fruited species (Ericaceae and Proteaceae) endemic to Western Australia

2008 ◽  
Vol 56 (6) ◽  
pp. 493 ◽  
Author(s):  
Melanie A. Norman ◽  
John M. Koch
Keyword(s):  
Western Australia ◽  
Seed Viability ◽  
Early Spring ◽  
Land Restoration ◽  
Jarrah Forest ◽  
Soil Burial ◽  
True Seed ◽  
Viable Seeds ◽  
Seed Fall

The woody-fruited species Leucopogon propinquus R.Br., Styphelia tenuiflora Lindl. (Ericaceae) and Persoonia longifolia R.Br. (Proteaceae) need to be returned to restored mines in Western Australia. All species have physiological seed dormancy, however germination has been observed following the application of smoke to native habitats. We recorded seed viability, permeability to water, endocarp strength, morphology and germination ± gibberellic acid (GA3) every 3 months for 24 months of in-situ burial in the jarrah forest to determine the time of dormancy release and corresponding seed changes. The term ‘seed’ refers to the woody endocarp, plus the true seed. Persoonia longifolia reached 37% germination after burial in soil for 21 months, followed by chipping the endocarp and GA3 application. A minimum of 15 months soil burial was necessary for unchipped seeds to germinate; 22% germination was achieved after 18 months burial in soil followed by GA3 application. Viability of fresh seeds of all three species was 96–100% and remained unchanged for P. longifolia, but declined to 5 and 0% following 24 months of soil burial for L. propinquus and S. tenuiflora, respectively. Germination of the two Ericaceae species was negligible, despite the presence of viable seeds (30–63%, depending on the species) after 12 months of soil burial and substantial deterioration of the endocarp. To germinate large quantities of P. longifolia, for use in land restoration, drupes should be buried in-situ in forest soil for 18 months immediately following seed fall (early spring) and GA3 treated, following exhumation.

scholarly journals Longevidad y germinación de semillas de Syagrus romanzoffiana (Arecaceae) y sus implicaciones ecológicas

2015 ◽  
Vol 63 (2) ◽  
pp. 333 ◽  
Author(s):  
Túlio Gabriel Soares Oliveira ◽  
Anderson Cleiton José ◽  
Leonardo Monteiro Ribeiro ◽  
José Marcio Rocha Faria
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Palm Tree ◽  
Forest Fragment ◽  
Seedling Mortality ◽  
Viable Seeds ◽  
One Year ◽  
Syagrus Romanzoffiana

<strong><em>Syagrus romanzoffiana</em> is a palm tree native and widely distributed of South America.</strong> <strong>The present study investigated the longevity and germination of the buried seeds of this species in an experimental seed bank.</strong> <strong>Laboratory germination and</strong> <strong>viability tests were performed for comparison with field results. Pyrenes (seeds enclosed by the endocarp) were buried in a forest fragment edge in July (dry season) in July 2012 and exhumed monthly during one year, for the assessment of water content</strong> <strong>and percentage of germinated and viable seeds.</strong> <strong>Germination tests</strong> <strong>were conducted in a Mangelsdorf-type germinator at 30°C under constant light and the viability was </strong><strong>assessed by the tetrazolium test. An additional sample of</strong> <strong>pyrenes was buried to evaluate the percentage of seedling emergence and survival. Climatic</strong> <strong>and soil moisture</strong> <strong>data</strong> <strong>were recorded.</strong> <strong>In the laboratory, the pyrenes were stored for one year in a temperature-controlled room at 20ºC and 75% (±10%) relative air humidity to assess changes in the percentage of germination and viability over time.</strong> <strong>In the field, a reduction in seed viability</strong> <strong>was observed over the study period, with a total loss of viability of non-germinated seeds at seven months after burial.</strong> <strong>The maximum germination (close to 26%) was observed in the samples that were exhumed between five and seven months after burial. In the field, seedling emergence did not exceed 10% and seedling mortality was not observed. The percentages of germination and of viable seeds decreased both in burial and stored seeds. The stored seeds maintained viability at up to six months, with marked reduction thereafter. After the germination tests (four months) in the laboratory, all of the remaining seeds were nonviable. The ecological, physiological</strong> <strong>and reproductive characteristics of the species are discussed, and we concluded that</strong> <strong><em>S. romanzoffiana</em></strong> <strong>seeds have short longevity after imbibition, and low potential for soil seed bank formation.</strong>

Environmental factors affecting the germination and seedling emergence of two populations of an emerging agricultural weed: wild lettuce (Lactuca serriola)

2019 ◽  
Vol 70 (8) ◽  
pp. 709 ◽  
Author(s):  
Aakansha Chadha ◽  
Singarayer Florentine ◽  
Bhagirath S. Chauhan ◽  
Benjamin Long ◽  
Mithila Jayasundera ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Crop Residues ◽  
Seedling Emergence ◽  
Detailed Knowledge ◽  
Burial Depth ◽  
Factors Affecting ◽  
Wild Lettuce ◽  
Lactuca Serriola ◽  
Environmental Weed ◽  
Two Populations

Wild lettuce (Lactuca serriola L.) is a significant emerging agricultural and environmental weed in many countries. This invasive species is now naturalised in Australia and is claimed to cause significant losses within the agricultural industry. Sustainable management of wild lettuce has been hampered by a lack of detailed knowledge of its seed ecology. Laboratory-based studies were performed to examine the potential influence of environmental factors including temperature and light conditions, salinity, pH, moisture availability and burial depth on the germination and emergence of two spatially distant populations of wild lettuce. Results suggested that the germination of wild lettuce seeds occurred across a broad range of temperature conditions (12-h cycle: 30°C/20°C, 25°C/15°C and 17°C/7°C) for both populations. We also found that these seeds are non-photoblastic; germination was not affected by darkness, with &gt;80% germination in darkness for both populations at all tested temperature ranges. Germination significantly declined as salinity and osmotic stress increased for both populations, with seeds from the Tempy population were more affected by NaCl &gt;100 mM than seeds from Werribee, but in neither population was there any observed effect of pH on germination (&gt;80% germination in both populations at all tested pH ranges). For both populations, germination significantly decreased as burial depth increased; however, the two populations differed with regard to response to burial depth treatment, whereby seeds from the Tempy population had higher emergence than those from Werribee at 0.5 cm burial depth. These results suggest that light-reducing management techniques such as mulching or use of crop residues will be unsuccessful for preventing germination of wild lettuce. By contrast, burial of seeds at a depth of at least 4 cm will significantly reduce their emergence.

Germination and emergence of common beggar’s-tick (Bidens alba) seeds at two different stages of afterripening as affected by environmental factors

Weed Science ◽  
2020 ◽  
Vol 68 (5) ◽  
pp. 503-509 ◽  
Author(s):  
Jialin Yu ◽  
Shaun M. Sharpe ◽  
Nathan S. Boyd
Keyword(s):  
Environmental Factors ◽  
Weed Management ◽  
Germination Rate ◽  
Integrated Control ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Moisture Stress ◽  
Burial Depth ◽  
Light Requirement ◽  
Osmotic Potentials

AbstractExperiments were conducted to determine the effect of various environmental factors and burial depth on germination and seedling emergence of common beggar’s-tick [Bidens alba (L.) DC.] seeds at two different stages of afterripening. Mature B. alba seeds were stored at 4 C for 3 to 5 mo (new seed lot) and 13 to 15 mo (old seed lot) until experiment initiation. Germination exponentially decreased with increasing moisture stress. Germination rate decreased from 87 ± 2.9% to 13 ± 6.1% as osmotic potential decreased from 0 to −0.5 MPa and was completely inhibited at osmotic potentials below −0.83 MPa. A large portion of the new seeds tested positively photoblastic, but seeds that had afterripened for 1 additional year were partially desensitized to the light requirement. New and old seeds still germinated to a greater percentage in the presence of light than under continuous dark at temperatures ranging from 15 to 35 C. Both new and old seeds germinated over a range of temperatures from 5 to 35 C, but the optimum temperatures for germination was 15 to 30 C in the presence of light. Regardless of seed lot, seedling emergence was the greatest when seeds were sown at the soil surface. Seedling emergence was abruptly reduced when burial depth was 1 cm or greater. Based on these results, we conclude that shallow cultivation could effectively suppress this population of B. alba from emerging when incorporated into an integrated control strategy. The information obtained in this research identifies some important factors that facilitate the widespread presence of B. alba in Florida and may contribute to weed management programs.

Effects of Environmental Factors on Seed Germination and Seedling Emergence of Common Teasel (Dipsacus fullonum)

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 421-429
Author(s):  
Héctor R. Huarte ◽  
María del R. Pereyra Zorraquín ◽  
Eric M. Bursztyn ◽  
María L. Zapiola
Keyword(s):  
Abscisic Acid ◽  
Environmental Factors ◽  
Seedling Emergence ◽  
Hormonal Control ◽  
Burial Depth ◽  
Synthesis Inhibitor ◽  
Physiological Dormancy ◽  
Temperature Requirements ◽  
Alternating Temperature ◽  
Seed Coats

Common teasel is an invasive and widespread weed in Argentina. Germination experiments were carried out from 2011 to 2014 to determine the effect of various environmental factors on germination and emergence. Germination of recently dispersed seeds was 12% in darkness at constant temperature. In contrast, seed exposure to light and alternating temperatures enhanced germination to 95%. The requirement of light and alternating temperatures suggest that common teasel has physiological dormancy. Several experiments were carried out to determine whether (1) seed responses to light and alternating temperatures have a hormonal basis, (2) seed coats can suppress germination, and (3) time and thermal conditions during seed storage reduce light and alternating temperature requirements. Germination was reduced (≤ 13%) by a gibberellin synthesis inhibitor. In contrast, the presence of gibberellins and an abscisic acid synthesis inhibitor increased germination to 95 and 38%, respectively. Results suggest that a higher ratio among gibberellins and abscisic acid (GA/ABA) leads to a break in dormancy. Germination was 100% when embryos were excised, suggesting that seed coats may suppress germination by mechanical restriction. Likewise, germination was enhanced by hydrogen peroxide (70%). This compound is known to increase GA/ABA ratio in agreement with a hormonal control of dormancy proposed for common teasel. An increment of storage time reduces light and alternating temperature requirements, allowing seeds to germinate in darkness. Taking these results together confirms that common teasel has physiological dormancy. Seedling emergence was progressively reduced from 70 to 8% by increased burial depth from 0 to 3 cm. Information from these experiments may facilitate development of effective management for common teasel.

Influence of Environmental Factors on Seed Germination and Seedling Emergence of American Sloughgrass (Beckmannia syzigachne)

Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 529-533 ◽  
Author(s):  
Na Rao ◽  
Liyao Dong ◽  
Jun Li ◽  
Hongjun Zhang
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Optimum Temperature ◽  
Ph Values

The influence of environmental factors on seed germination and seedling emergence of American sloughgrass was studied in laboratory and greenhouse conditions. The optimum temperature for seed germination was 10 C and light was not necessary. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was quite tolerant to salinity: germination occurred even at 160 mM NaCl (36%). More than 80% of seeds germinated at pH values ranging between 4 and 10. Seedling emergence was highest when seeds were placed on the soil surface (91%) but declined with burial depth. Few (3%) seedlings emerged when seeds were planted at a depth of 5 cm. Information gained in this study will lead to a better understanding of the requirements for American sloughgrass germination and emergence.

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