Buttonweed emergence as affected by seed burial depth and straw on the soil surface

Horse purslane, a C4 species, is a branched, prostrate, and annual weed of upland field crops throughout the tropics. Experiments were conducted to determine the influence of various environmental factors on seed germination and seedling emergence of two populations of horse purslane. Seeds were collected from rice fields of the International Rice Research Institute (the IR population) and from sorghum fields of the University of the Philippines (the UP population); the two sites were 5 km apart in Los Baños, Philippines. Germination response of both populations was greater at 30/20 C and35/25 C day/night temperatures than they were at 25/15 C alternating day/night temperatures. Germination of both populations was greater in the light/dark regime than in darkness. In dark, depending on the temperature, seed germination of the UP population ranged from 37 to 62%, whereas seed germination of the IR population was < 20%. Exposure to 5 min at 117 and 119 C for the IR and UP populations, respectively, reduced germination to 50% of maximum germination. Osmotic potential of −0.26 MPa inhibited germination to 50% of the maximum for the UP population, whereas the corresponding value for the IR population was −0.37 MPa. Seeds placed on or near the soil surface had maximum emergence, and emergence declined with increase in seed burial depth. Seedling emergence of the UP and IR populations was 74% and 13%, respectively, for seeds placed on the soil surface. For both populations, no seedlings emerged from a soil burial depth of 6 cm or more. Germination and emergence responses to light and seed burial depth differed between the two populations of horse purslane. Residues on the soil surface of up to 6 Mg ha−1 did not influence seedling emergence of either populations. Knowledge gained in this study could contribute to developing components of integrated weed management strategies for horse purslane.

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Weedy rice (Oryza sativa) II. Response of Weedy Rice to Seed Burial and Flooding Depth

Weed Science ◽

10.1614/ws-d-11-00213.1 ◽

2012 ◽

Vol 60 (3) ◽

pp. 385-388 ◽

Cited By ~ 16

Author(s):

Bhagirath Singh Chauhan

Keyword(s):

Seedling Emergence ◽

Soil Surface ◽

Production Costs ◽

The Other ◽

Weedy Rice ◽

Burial Depth ◽

Rice Accession ◽

Seed Burial ◽

Seedling Biomass ◽

Flooding Depth

Weedy rice is a serious problem of cultivated rice in most of the rice-growing areas in Asia, causing increased production costs and yield losses in rice. A study was conducted to determine the response of weedy rice accessions from India (IWR), Malaysia (MWR), Thailand (TWR), and Vietnam (VWR) to seed burial and flooding depths. The greatest emergence for each weedy rice accession (97% for IWR, 82% for MWR, 97% for TWR, and 94% for VWR) was observed in seeds placed on the soil surface. Seedling emergence decreased with increase in burial depth. For the IWR accession, 0.5% of the seedlings emerged from 8-cm depth, whereas for the other three weedy rice accessions, no seedlings emerged from this depth. When seeds were sown on the soil surface, flooding depth ranging from 0 to 8 cm had no or very little effect on seedling emergence of different weedy rice accessions. On the other hand, flooding decreased seedling emergence in all weedy rice accessions when seeds were sown at 1 cm deep into the soil. Compared with seedling emergence, flooding had a more pronounced effect on seedling biomass for all weedy rice accessions. A flooding depth of 2 cm reduced seedling biomass by an amount greater than 85% of each weedy rice accession. The results of this study suggest that emergence and growth of weedy rice could be suppressed by deep tillage that buries seeds below their maximum depth of emergence (i.e., > 8 cm for the accessions studied) and by flooding fields as early as possible. The information gained from this study may help design cultural management strategies for weedy rice in Asia.

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Influence of Seed Depth and Pathogens on Fatal Germination of Velvetleaf (Abutilon theophrasti) and Giant Foxtail (Setaria faberi)

Weed Science ◽

10.1614/w-06-099.1 ◽

2007 ◽

Vol 55 (1) ◽

pp. 30-35 ◽

Cited By ~ 32

Author(s):

Adam S. Davis ◽

Karen A. Renner

Keyword(s):

Soil Surface ◽

Pathogenic Fungi ◽

Pythium Ultimum ◽

Burial Depth ◽

Field Soil ◽

Seed Fate ◽

Seed Burial ◽

Setaria Faberi ◽

Giant Foxtail ◽

Unsterilized Soil

Fatal germination of weed seeds occurs when a weed seed germinates, but the seedling dies before reaching the soil surface. Controlled-environment bioassays of velvetleaf and giant foxtail seed fate in Michigan field soil (Kalamazoo silt loam, 1.1% soil organic matter) were used to determine the role of pathogenic fungi and seed burial depth in fatal germination of these species. Fatal germination at 2 cm seed depth was nonexistent for giant foxtail, and rare (< 10% of seeds studied) for velvetleaf. At greater depths, fatal germination remained close to zero for giant foxtail, whereas it increased to as high as 40% for velvetleaf at a 10-cm burial depth. Cultures taken from fatally germinated velvetleaf seedlings were found to containPythium ultimum, a soilborne pathogen known as the causal agent for pea root rot. When samples of infected media taken from these cultures were used to inoculate field soil in pots, fatal germination of velvetleaf from depths of 4 to 6 cm increased, compared with field soil inoculated with sterile media. At seed burial depths of 8 and 10 cm, fatal germination of velvetleaf increased to 20 and 40%, respectively, and was the same for unsterilized soil andP. ultimum–inoculated soil. Given that maximal fatal germination of velvetleaf occurred in the unsterilized soil treatment at the 10 cm depth, burial of newly shed velvetleaf seeds to a 10 cm, or possibly greater, depth with tillage equipment may be a practical way of reducing velvetleaf seed banks through fatal germination.

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Depth of Seed Burial and Gender Influence Weed Seed Predation by Three Species of Ground Beetle (Coleoptera: Carabidae)

Weed Science ◽

10.1614/ws-d-15-00080.1 ◽

2015 ◽

Vol 63 (4) ◽

pp. 910-915 ◽

Cited By ~ 14

Author(s):

Sharavari S. Kulkarni ◽

Lloyd M. Dosdall ◽

John R. Spence ◽

Christian J. Willenborg

Keyword(s):

Seed Predation ◽

Ground Beetle ◽

Soil Surface ◽

Ground Beetles ◽

Burial Depth ◽

Weed Seed ◽

Seed Burial ◽

Buried Seeds ◽

Pterostichus Melanarius ◽

And Gender

Ground beetles are postdispersal weed seed predators, yet their role in consuming buried seeds is not well studied. We conducted greenhouse experiments to investigate how seed burial affects consumption of weed seeds (volunteer canola) by adult ground beetles (Coleoptera: Carabidae). Seed burial depth influenced seed consumption rates as demonstrated by a significant interaction between seed burial depth, carabid species, and gender of the carabid tested. We observed higher seed consumption by females of all species, and greater consumption of seeds scattered on the soil surface compared with seeds buried at any depth. However, there was evidence of seed consumption at all depths. Adults ofPterostichus melanarius(Illiger) andHarpalus affinis(Schrank) consumed more buried seeds than did those ofAmara littoralisMannerheim. Agricultural practices, such as tillage, bury seeds at different depths and based on the results of this study, these practices may reduce seed consumption by carabids. Soil conservation practices that reduce tillage (conservation or zero tillage) will favor greater weed seed predation due, in part, to the high availability of seeds at the soil surface or at shallow soil depths.

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

Plant Species Biology ◽

10.1111/1442-1984.12321 ◽

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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Seasonal cycles in germination and seedling emergence of summer and winter populations of catchweed bedstraw (Galium aparine) and wild mustard (Brassica kaber)

Weed Science ◽

10.1614/ws-05-107r1.1 ◽

2006 ◽

Vol 54 (1) ◽

pp. 114-120 ◽

Cited By ~ 50

Author(s):

Husrev Mennan ◽

Mathieu Ngouajio

Keyword(s):

Soil Depth ◽

Cropping Systems ◽

Seedling Emergence ◽

Seed Mass ◽

Soil Surface ◽

Burial Depth ◽

Galium Aparine ◽

Wild Mustard ◽

Seed Population ◽

Brassica Kaber

Catchweed bedstraw and wild mustard each produce two populations per year: a winter population (WP) in June, and a summer population (SP) in September. Experiments were conducted to determine whether the WP and SP differ in seed mass and seasonal germination. Seeds of both weeds were buried at 0, 5, 10, and 20 cm in cultivated fields, and retrieved at monthly intervals for 24 mo for germination tests in the laboratory. Additionally, seedling emergence from seeds buried at 0, 5, and 10 cm in the field was evaluated for 1 yr. Seeds from the WP were heavier than those from the SP for both species. Germination of exhumed seeds was affected by burial depth and by seed population. It was highest for seeds that remained on the soil surface and declined with increasing depth of burial. The WP of catchweed bedstraw produced two germination peaks per year, whereas the SP and all populations of wild mustard had only one peak. The WP of both weeds germinated earlier than the SP. Seedling emergence for both species in the field was greater for the WP than for the SP. Increasing soil depth reduced seedling emergence of both the WP and SP of wild mustard and affected only the WP of catchweed bedstraw. We conclude that the WP and SP of catchweed bedstraw and wild mustard seeds used in this study differed in seed mass, seasonal germination, and seedling emergence. The ability of a WP to produce large seeds that germinate early and have two germination peaks per year could make these populations a serious problem in cropping systems.

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Survival of Fusarium moniliforme, F. proliferatum, and F. subglutinans in Maize Stalk Residue

Phytopathology ◽

10.1094/phyto.1998.88.6.550 ◽

1998 ◽

Vol 88 (6) ◽

pp. 550-555 ◽

Cited By ~ 71

Author(s):

T. K. Cotten ◽

G. P. Munkvold

Keyword(s):

Fusarium Moniliforme ◽

Fusarium Species ◽

Soil Surface ◽

Selective Medium ◽

Burial Depth ◽

Linear Pattern ◽

Maize Field ◽

Continuous Maize ◽

Maize Plants

The roles of residue size and burial depth were assessed in the survival of Fusarium moniliforme, F. proliferatum, and F. subglutinans in maize stalk residue. Stalk pieces (small or large sizes) were soaked in a spore suspension of F. moniliforme, F. proliferatum, or F. subglutinans and placed in a field on the soil surface or buried at 15- or 30-cm depths. Residue pieces were recovered periodically, cultured on a selective medium, and microscopically examined for the presence of the inoculated Fusarium species. After 630 days, the inoculated Fusarium species were recovered from 0 to 50% of the inoculated stalk pieces in a long-term, continuous maize field, from 0 to 28% of the inoculated stalk pieces placed in a maize/soybean/oat rotation field, and from 0 to 25% of the noninoculated stalk pieces at both locations. Residue size and residue depth had significant effects on survival, but there were significant interactions among strain, depth, residue size, and time. Up to 343 days after placement in the field, survival of the three Fusarium species was not consistently different between buried residues and surface residues, but after 630 days, survival was greater from surface residues. Overall, fungus survival decreased more slowly in the surface residues than in the buried residues. Linear coefficients of determination ranged from 0.35 to 0.82 for the surface residues and from 0.81 to 0.98 for the buried residues. Decline in survival over time followed a more linear pattern in buried residues than in surface residues. Vegetative compatibility tests confirmed that F. moniliforme, F. proliferatum, and F. subglutinans strains can survive at least 630 days in surface or buried maize residue. These results demonstrate that maize residue can act as a long-term source of inoculum for infection of maize plants by these three Fusarium species.

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Effect of Environmental Factors on Germination and Emergence of Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽

10.1017/wsc.2017.42 ◽

2017 ◽

Vol 66 (1) ◽

pp. 47-56 ◽

Cited By ~ 12

Author(s):

Ning Zhao ◽

Qi Li ◽

Wenlei Guo ◽

Lele Zhang ◽

Lu’an Ge ◽

...

Keyword(s):

Seed Germination ◽

Osmotic Potential ◽

Control Strategies ◽

Abiotic Factors ◽

Germination Rate ◽

Seedling Emergence ◽

Soil Surface ◽

Burial Depth ◽

Effective Measure ◽

Wide Range

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.

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Seed Germination Ecology of Itchgrass (Rottboellia cochinchinensis)

Weed Science ◽

10.1614/ws-d-10-00095.1 ◽

2011 ◽

Vol 59 (2) ◽

pp. 182-187 ◽

Cited By ~ 30

Author(s):

Grace E-K. Bolfrey-Arku ◽

Bhagirath S. Chauhan ◽

David E. Johnson

Keyword(s):

High Temperature ◽

Seed Germination ◽

Seedling Emergence ◽

Soil Surface ◽

The Philippines ◽

Integrated Weed Management ◽

Burial Depth ◽

Soil Burial ◽

Dark Regime ◽

Temperature Pretreatment

Itchgrass is a weed of many crops throughout the tropics and one of the most important grass weeds of rainfed rice. Experiments were conducted in the laboratory and screenhouse to determine the effects of light, alternating day/night temperatures, high temperature pretreatment, water stress, seed burial depth, and rice residue on seed germination and seedling emergence of itchgrass in the Philippines. Two populations were evaluated and the results were consistent for both populations. Germination in the light/dark regime was greater at alternating day/night temperatures of 25/15 C than at 35/25, 30/20, or 20/10 C. Light was not a requirement for germination, but a light/dark regime increased germination by 96%, across temperature and population. A 5-min high temperature pretreatment for 50% inhibition of maximum itchgrass germination ranged from 145 to 151 C with no germination when seeds were exposed to ≥ 180 C. The osmotic potential required for 50% inhibition of maximum germination was −0.6 MPa for itchgrass, although some seeds germinated at −0.8 MPa. Seedling emergence was greatest for seeds placed on the soil surface, and emergence declined with increasing soil burial depth; no seedlings emerged from seeds buried at 10 cm. The addition of rice residue to soil surface in pots at rates equivalent to 4 to 6 Mg ha−1reduced itchgrass seedling emergence. Since seedling emergence was greatest at shallow depths and germination was stimulated by light, itchgrass may become a problem in systems where soil is cultivated at shallow depths. Knowledge gained in this study could contribute to developing components of integrated weed management strategies for itchgrass.

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Numerical analysis of soil deformation behind the reaction wall of an open caisson induced by horizontal parallel pipe-jacking construction

Canadian Geotechnical Journal ◽

10.1139/cgj-2015-0024 ◽

2015 ◽

Vol 52 (12) ◽

pp. 2008-2016 ◽

Cited By ~ 5

Author(s):

Yang Sun ◽

Jing-bo Su ◽

Xiao-he Xia ◽

Zheng-liang Xu

Keyword(s):

Reaction Force ◽

Soil Surface ◽

Horizontal Displacement ◽

Element Model ◽

Deformation Analysis ◽

Burial Depth ◽

Maximum Displacement ◽

Obvious Effect ◽

Simple Loading ◽

Pipe Jacking

The disturbance of the soil behind the reaction wall of an open caisson can affect the efficiency and safety of jacking operation and control. This study focuses on the deformation of the soil mass behind the reaction wall used to support the jack. The stress–strain relationship of the soil behind the reaction wall was analysed, providing a theoretical basis for determining the most unfavourable combination of reactive forces using a computational model. A three-dimensional finite element model for this problem was developed, and a simple loading scenario was implemented. In addition, the mechanism of the deformation of the soil induced by horizontal parallel pipe jacking was also analysed. The results showed that for the soil behind the reaction wall of the open caisson, the uplift deformation of the soil surface increased initially and later gradually decreased, eventually achieving stability. The reaction force had a relatively obvious effect on the deformation of the soil within the range of the reaction wall burial depth and the horizontal displacement of the soil along the length of the reaction wall. The maximum displacement occurred near the axis of symmetry of the reaction wall. In addition, to consider the cyclic characteristics of the reaction force, the shakedown theorem is introduced to the deformation analysis of the soil and compared with the results obtained from simple loading. It was shown that the two deformation analysis methods have certain scopes of application, depending on the individual engineering requirements.

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