scholarly journals Effects of Burial Depth and Substrate on the Emergence of Bromus rubens and Brassica tournefortii

2011 ◽  
Vol 110 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Scott R. Abella ◽  
Amber C. Lee ◽  
Alexis A. Suazo
Keyword(s):  
Burial Depth ◽  
Brassica Tournefortii ◽  
Bromus Rubens

Biology of Brassica tournefortii in the northern grains region of Australia

2020 ◽  
Vol 71 (3) ◽  
pp. 268
Author(s):  
Gulshan Mahajan ◽  
Rajandeep Singh ◽  
Bhagirath S. Chauhan
Keyword(s):  
Soil Depth ◽  
Integrated Management ◽  
Management Strategies ◽  
Burial Depth ◽  
Hordeum Vulgare L ◽  
Tillage Systems ◽  
No Till ◽  
Short Period ◽  
Buried Seeds ◽  
Brassica Tournefortii

Brassica tournefortii Gouan. (wild turnip, WT) has become a problematic weed in the no-till production systems of the northern grains region of Australia. Experiments were undertaken using different biotypes of B. tournefortii to examine its phenology, emergence and seedbank persistence. Biotypes were obtained from paddocks of barley (Hordeum vulgare L.) (WT1 and WT9) and chickpea (Cicer arietinum L.) (WT1/17 and WT2/17). Fresh seeds initially had high dormancy rates and persisted for a short period on the surface. Seedbank persistence increased with burial depth, with 39% of seeds remaining for WT1 and 5% for WT9 after 30 months at 2 cm depth. Persistence of buried seeds varied across biotypes; WT1/17 seedlings also emerged in the second growing season from 2 cm depth. Compared with buried seeds, seedlings readily emerged from the surface (in March–June following increased rainfall) within 6 months of planting. Emergence was greatest on the surface and varied between biotypes and tillage systems; the highest rate recorded was ~14%. Multiple cohorts were produced between February and October. No-till systems produced higher emergence rates than conventional tillage systems. Seedlings of B. tournefortii did not emerge from 5 cm soil depth; therefore, diligent tillage practices without seedbank replenishment could rapidly reduce the presence of this weed. A soil-moisture study revealed that at 25% of water-holding capacity, B. tournefortii tended to produce sufficient seeds for reinfestation in the field. Brassica tournefortii is a cross-pollinated species, and its wider emergence time and capacity to produce enough seeds in a dry environment enable it to become widespread in Australia. Early cohorts (March) tended to have vigorous growth and high reproduction potential. This study found B. tournefortii to be a poor competitor of wheat (Triticum aestivum L.), having greater capacity to compete with the slow-growing crop chickpea. Therefore, control of early-season cohorts and use of rotations with a more vigorous crop such as wheat may reduce the seedbank. The information gained in this study will be important in developing better understanding of seed ecology of B. tournefortii for the purpose of developing integrated management strategies.

Climate Change May Alter Both Establishment and High Abundance of Red Brome (Bromus rubens) and African Mustard (Brassica tournefortii) in the Semiarid Southwest United States

2015 ◽  
Vol 8 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Caroline A. Curtis ◽  
Bethany A. Bradley
Keyword(s):  
United States ◽  
Invasive Plants ◽  
High Abundance ◽  
High Threshold ◽  
Climatic Suitability ◽  
Worst Case ◽  
Red Brome ◽  
Brassica Tournefortii ◽  
Bromus Rubens ◽  
Low Threshold

AbstractNonnative, invasive plants are becoming increasingly widespread and abundant throughout the southwestern United States, leading to altered fire regimes and negative effects on native plant communities. Models of potential invasion are pertinent tools for informing regional management. However, most modeling studies have relied on occurrence data, which predict the potential for nonnative establishment only and can overestimate potential risk. We compiled locations of presence and high abundance for two problematic, invasive plants across the southwestern United States: red brome (Bromus rubens L.) and African mustard (Brassica tournefortii Gouan). Using an ensemble of five climate projections and two types of distribution model (MaxEnt and Bioclim), we modeled current and future climatic suitability for establishment of both species. We also used point locations of abundant infestations to model current and future climatic suitability for abundance (i.e., impact niche) of both species. Because interpretations of future ensemble models depend on the threshold used to delineate climatically suitable from unsuitable areas, we applied a low threshold (1 model of 10) and a high threshold (6 or more models of 10). Using the more-conservative high threshold, suitability for Bromus rubens presence expands by 12%, but high abundance contracts by 42%, whereas suitability for Brassica tournefortii presence and high abundance contract by 34% and 56%, respectively. Based on the low threshold (worst-case scenario), suitability for Bromus rubens presence and high abundance are projected to expand by 65% and 64%, respectively, whereas suitability for Brassica tournefortii presence and high abundance expand by 29% and 28%, respectively. The difference between results obtained from the high and low thresholds is indicative of the variability in climate models for this region but can serve as indicators of best- and worst-case scenarios.

scholarly journals Distribución potencial de ocho especies exóticas de carácter invasor en el estado de Baja California, México

2014 ◽  
Vol 92 (4) ◽  
pp. 587 ◽  
Author(s):  
Sara Palma-Ordaz ◽  
José Delgadillo-Rodríguez
Keyword(s):  
Baja California ◽  
Cynodon Dactylon ◽  
Tamarix Ramosissima ◽  
Brassica Tournefortii ◽  
Bromus Rubens ◽  
Para Determinar ◽  
Schismus Barbatus

<p>Se determinó la distribución potencial de ocho especies exóticas de carácter invasor en el estado de Baja California (<em>Atriplex semibaccata</em>, <em>Brassica tournefortii</em>, <em>Bromus rubens</em>, <em>Centaurea melitensis</em>, <em>Cynodon dactylon</em>, <em>Salsola tragus</em>, <em>Schismus barbatus</em> y <em>Tamarix ramosissima</em>), mediante el uso del programa de modelaje MaxEnt. Para ello se utilizaron 19 variables climáticas y la distribución conocida de las especies, obtenida de registros de herbario. Todos los modelos fueron evaluados para probar su habilidad de predicción y se analizaron las variables climáticas más importantes en el modelo predictivo de cada especie. Se identificó la zona costera noroeste (zona mediterránea), como el área de mayor probabilidad de presencia de las especies. Esto puede deberse a que es una zona en donde históricamente el intercambio florístico ha sido más intensivo y donde la actividad antropogénica es mayor; además, probablemente estas especies han tenido una mejor adaptación a las condiciones climáticas de la zona, sólo algunas de ellas extienden su distribución potencial hacia las regiones desérticas del estado. Este es el primer trabajo que se realiza en Baja California, que considera las especies exóticas y su potencial invasor a partir de modelos de distribución potencial. Estos modelos, definidos con la información actual disponible, pueden apoyar para determinar los sitios más importantes de concentración de las mismas.</p>

Germination Ecology of Four African mustard (Brassica tournefortii Gouan.) Populations in the Eastern Region of Australia

Weed Science ◽  
2021 ◽  
pp. 1-28
Author(s):  
Sohraab Singh ◽  
Gulshan Mahajan ◽  
Rajandeep Singh ◽  
Bhagirath S. Chauhan
Keyword(s):  
Temperature Regime ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Chloride Concentration ◽  
Burial Depth ◽  
Eastern Region ◽  
Germination Ecology ◽  
Wide Range ◽  
Brassica Tournefortii ◽  
Winter Annual

Abstract African mustard (Brassica tournefortii Gouan) is a problematic winter annual weed in Australia. Germination ecology of B. tournefortii may change in response to the maternal environments or habitats in which they grow. A study was conducted to evaluate the effect of environmental factors on germination and emergence of four populations of B. tournefortii that were collected from different fields. Averaged over populations, germination was stimulated by dark and was higher at 25/15 C (92%) as compared with 15/5 C (76%) and 35/25 C (45%). Averaged over light/dark regimes, at the lowest temperature regime (15/5 C), population A had higher germination than population D ; however, at the highest temperature regime (35/25 C), population D had higher germination than population A. Population B and C had higher germination in the temperature range of 25/15 C and 30/20 C compared with 15/5 C, 20/10 C, and 35/25 C. Seeds germinated at a wide range of alternating day/night temperatures (15/5 to 35/25 C), suggesting that seeds can germinate throughout the year if other optimum conditions are available. Population A was more tolerant to water and salt stress than population D. The sodium chloride concentration and osmotic potential required to inhibit 50% germination of population A was 68 mM and -0.60 MPa, respectively. Averaged over populations, seeds placed at 1cm soil depth had the highest emergence (54%), and burial depth of 8 cm resulted in 28% seedling emergence. Averaged over populations, wheat residue retention at 6000 kg ha-1 resulted in greater seedling emergence than the residue amount of 1000 kg ha-1. The results suggest that B. tournefortii will be favored in no-till systems and the seed bank of B. tournefortii could be managed by tillage regimes that bury its seeds below 8 cm depths and restrict seedling emergence and growth of new plants.

scholarly journals Fluid inclusions in buried quartz of the Yanchang sandstone in the Jiyuan area, Ordos Basin, China: Implications for basin evolution and petroleum accumulation

2020 ◽  
pp. 014459872097451
Author(s):  
Wenqi Jiang ◽  
Yunlong Zhang ◽  
Li Jiang
Keyword(s):  
Fluid Inclusions ◽  
Ordos Basin ◽  
Homogenization Temperature ◽  
Burial Depth ◽  
Hydrocarbon Generation ◽  
Rock Interaction ◽  
Yanchang Formation ◽  
Reflection Data ◽  
And Migration ◽  
Vitrinite Reflection

A fluid inclusion petrographic and microthermometric study was performed on the sandstones gathered from the Yanchang Formation, Jiyuan area of the Ordos Basin. Four types of fluid inclusions in quartz can be recognized based on the location they entrapped. The petrographic characteristics indicate that fluid inclusions in quartz overgrowth and quartz fissuring-I were trapped earlier than that in quartz fissuring-IIa and fissuring-IIb. The homogenization temperature values of the earlier fluid inclusions aggregate around 80 to 90°C; exclusively, it is slightly higher in Chang 6 member, which approaches 95°C. The later fluid inclusions demonstrate high homogenization temperatures, which range from 100 to 115°C, and the temperatures are slightly higher in Chang 9 member. The calculated salinities show differences between each member, including their regression characteristics with burial depth. Combining with the vitrinite reflection data, the sequence and parameters of fluid inclusions indicate that the thermal history of the Yanchang formation mostly relied on burial. Salinity changes were associated with fluid-rock interaction or fluid interruption. Hydrocarbon contained fluid inclusions imply that hydrocarbon generation and migration occurred in the Early Cretaceous. The occurrence of late fluid inclusions implied that quartz cement is a reservoir porosity-loose factor.

scholarly journals On the Dragging Trajectory of Anchors in Clay for Merchant Ships

2021 ◽  
Vol 9 (2) ◽  
pp. 118
Author(s):  
Xinqing Zhuang ◽  
Keliang Yan ◽  
Pan Gao ◽  
Yihua Liu
Keyword(s):  
Mathematical Model ◽  
Structural Integrity ◽  
Indirect Measurement ◽  
Test System ◽  
Flow Rule ◽  
Burial Depth ◽  
Proposed Model ◽  
Depth Increase ◽  
Two Parameters ◽  
The Mathematical Model

Anchor dragging is a major threat to the structural integrity of submarine pipelines. A mathematical model in which the mechanical model of chain and the bearing model of anchor were coupled together. Based on the associated flow rule, an incremental procedure was proposed to solve the spatial state of anchor until it reaches the ultimate embedding depth. With an indirect measurement method for the anchor trajectory, a model test system was established. The mathematical model was validated against some model tests, and the effects of two parameters were studied. It was found that both the ultimate embedding depth of a dragging anchor and the distance it takes to reach the ultimate depth increase with the shank-fluke pivot angle, but decrease as the undrained shear strength of clay increases. The proposed model is supposed to be useful for the embedding depth calculation and guiding the design of the pipeline burial depth.

scholarly journals Kombucha fermentation of African mustard (Brassica tournefortii) leaves: Chemical composition and bioactivity

2019 ◽  
Vol 30 ◽  
pp. 100414 ◽  
Author(s):  
Rami Rahmani ◽  
Sandra Beaufort ◽  
Silvia Alejandra Villarreal-Soto ◽  
Patricia Taillandier ◽  
Jalloul Bouajila ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Brassica Tournefortii

Germination and emergence of Astrodaucus orientalis (L.) Drude populations influenced by environmental factors and seed burial depth

2021 ◽  
Vol 36 (2) ◽  
pp. 338-347
Author(s):  
Rouhollah Amini ◽  
Atefeh Ebrahimi ◽  
Adel Dabbagh Mohammadi Nasab
Keyword(s):  
Environmental Factors ◽  
Burial Depth ◽  
Seed Burial
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