scholarly journals Factors affecting Cyperus difformis seed germination and seedling emergence

2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Weed Species ◽  
Factors Affecting ◽  
Cyperus Difformis ◽  
Emergence Patterns

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.

Seed Germination and Seedling Recruitment Behavior of Winged Sea Lavender (Limonium lobatum) in Southern Australia

Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 485-493 ◽  
Author(s):  
Samuel G. L. Kleemann ◽  
Gurjeet Gill
Keyword(s):  
Seed Germination ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Base Temperature ◽  
Weed Species ◽  
Factors Affecting ◽  
Weed Seeds ◽  
Sea Lavender ◽  
C 50

AbstractWinged sea lavender [Limonium lobatum(L.f. Chaz)] is emerging as a significant weed of field crops in southern Australia. Several environmental factors affecting germination and seedling recruitment were examined to provide a better understanding of the behavior of its seedbank. At maturity, weed seeds were dormant for a period of around 2 mo, but dormancy was easily broken with scarification or by pretreatment with 564 mM NaOCL for 30 min, which confirms the role of the seed coat in regulating seed germination. Exposure to light significantly increased germination. Seeds were able to germinate over a broad range of temperatures (5 to 30 C), with maximum germination (~92%) at temperatures between 10 and 30 C. At 20 to 25 C, 50% germination was reached within 1.3 to 2 d, and the predicted base temperature for germination of the two populations ranged from 1.4 to 3.9 C. The NaCl concentration required to inhibit germination by 50% was 230 mM, with some seeds capable of germination at salinity levels as high as 480 mM. These results indicated greater tolerance to salinity inL. lobatumthan many other Australian agricultural weed species previously investigated. Seedling emergence was the highest (51% to 57%) for seeds present on the soil surface and was significantly reduced by burial at 1 cm (≤11%) and 2 cm (≤2%), with no emergence at 5 cm. Under field conditions, seedling recruitment varied considerably among the three experimental sites. The level of seedling recruitment was negatively associated with rainfall received at the site, organic carbon (OC) level, and microbial biomass of the soil. Rapid decay of weed seeds in high-OC soils appears to be an important determinant of seedling recruitment in this species and could explain greater occurrence ofL. lobatumon soils with low OC and low microbial activity in low-rainfall areas of southern Australia. Furthermore, many such soils in southern Australia are affected by salinity, which would enableL. lobatumto be more competitive with crops and other weeds present at a site.

Factors affecting germination of jointed goatgrass (Aegilops cylindrica) seed

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 677-684 ◽  
Author(s):  
Lynn Fandrich ◽  
Carol A. Mallory-Smith
Keyword(s):  
Incubation Temperature ◽  
Integrated Management ◽  
Germination Rate ◽  
Management Strategies ◽  
Germination Percentage ◽  
Weed Species ◽  
Planting Depth ◽  
Dark Light ◽  
Factors Affecting ◽  
Jointed Goatgrass

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. The after-ripening period for jointed goatgrass seed was quantified, and the effects of germination conditions and spikelet structures on jointed goatgrass seed germination were measured. As the duration of after-ripening increased, jointed goatgrass seed germinated earlier, at faster rates, and to greater final percentages compared to non–after-ripened seed. Both primary and secondary positioned seed within jointed goatgrass spikelets were nondormant after 16 wk after-ripening at 22 ± 2 C. Germination of dormant seed depended on incubation temperature and dark/light conditions. Sixty-seven percent of spikelets produced a radicle when exposed to low temperatures in the dark, and light at warm temperatures increased germination by 7%. The relationship between light and incubation temperature was similar also for germination of the primary positioned seed in nondormant spikelets; however, the magnitude of the effect increased. Light increased germination of seed incubated at warm temperatures by 18%. Coleoptile emergence was dependent on planting depth for three jointed goatgrass populations, winter wheat, and spring wheat. Under optimum conditions in the greenhouse, no planting depth selectively allowed wheat germination and emergence while preventing jointed goatgrass germination and emergence. Glume removal increased jointed goatgrass secondary positioned seed final germination percentage to 96%, increased the germination rate, and decreased the number of days required to reach 50% germination to 6 d. Glume removal also promoted germination of the primary seed within jointed goatgrass spikelets. Glume removal resulted in 80% of the spikelets having two coleoptiles, but did not alleviate dormancy completely in jointed goatgrass seed. Tillage and herbicide applications for jointed goatgrass control will be most effective in the fall when primary dormancy is lost, but before secondary dormancy is imposed.

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

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
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.

scholarly journals Seed germination ecology of Conyza stricta Willd. and implications for management

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244059
Author(s):  
Safdar Ali ◽  
Fakhar Din Khan ◽  
Rehmat Ullah ◽  
Rahmat Ullah Shah ◽  
Saud Alamri ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Cropping Systems ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Conservation Agriculture ◽  
Weed Species ◽  
Seed Burial ◽  
Germination Ecology ◽  
Tillage Practices

Numerous cropping systems of the world are experiencing the emergence of new weed species in response to conservation agriculture. Conyza stricta Willd. is being a newly emerging weed of barley-based cropping systems in response to conservational tillage practices. Seed germination ecology of four populations (irrigated, rainfed, abandoned and ruderal habitats) was studied in laboratory and greenhouse experiments. The presence/absence of seed dormancy was inferred first, which indicated seeds were non-dormant. Seed germination was then recorded under various photoperiods, constant and alternating day/night temperatures, and pH, salinity and osmotic potential levels. Seedling emergence was observed from various seed burial depths. Seeds of all populations proved photoblastic and required 12-hour light/dark period for germination. Seeds of all populations germinated under 5–30°C constant temperature; however, peak germination was recorded under 17.22–18.11°C. Nonetheless, the highest germination was noted under 20/15°C alternating day/night temperature. Ruderal and irrigated populations better tolerated salinity and germinated under 0–500 mM salinity. Similarly, rainfed population proved more tolerant to osmotic potential than other populations. Seeds of all populations required neutral pH for the highest germination, whereas decline was noted in germination under basic and alkaline pH. Seedling emergence was retarded for seeds buried >2 cm depth and no emergence was recorded from >4 cm depth. These results add valuable information towards our understanding of seed germination ecology of C. stricta. Seed germination ability of different populations under diverse environmental conditions suspects that the species can present severe challenges in future if not managed. Deep seed burial along with effective management of the emerging seedlings seems a pragmatic option to manage the species in cultivated fields. However, immediate management strategies are needed for rest of the habitats.

scholarly journals Impact of Environmental Factors on Seed Germination and Seedling Emergence of White Clover (Trifolium repens L.)

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
White Clover ◽  
Trifolium Repens ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
High Sensitivity ◽  
Series Of Experiments ◽  
Trifolium Repens L

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.

scholarly journals Seed Germination, Seedling Emergence, and Response to Herbicides of Triquetrous Murdannia (Murdannia triquetra) in Rice

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Wei Tang ◽  
Jie Chen ◽  
Jianping Zhang ◽  
Yongliang Lu
Keyword(s):  
Seed Germination ◽  
Weed Management ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Rice Fields ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Nacl Concentration ◽  
Dark Regime

Triquetrous murdannia is an annual weed commonly found in rice fields in China. Laboratory and screenhouse experiments were carried out to determine the effect of light, temperature, osmotic and salt stress, seed burial depth, amount of rice residue, and depth of flooding on seed germination and seedling emergence of triquetrous murdannia and to evaluate the response of this weed to commonly available POST herbicides in China. Germination was greater than 93% under a wide day/night temperature range of 20/10 to 30/20 C in the light/dark regime. The time to onset of germination decreased as temperature increased. Germination was slightly stimulated when seeds were placed in light/dark conditions compared with seeds placed in the dark. The osmotic potential and NaCl concentration required for 50% inhibition of maximum germination were −0.5 MPa and 122 mM, respectively. The highest germination (68%) was observed from seeds sown on the soil surface, but decreased with increasing burial depth. Only 7% of seedlings emerged from a depth of 4 cm, and no seedlings emerged from seeds buried deeper than 6 cm. Seedling emergence decreased from 93 to 35% with increasing quantity of rice residue (1 to 6 103kg ha−1) applied on the soil surface. Seedling emergence was reduced by 40, 48, 64, and 70% at flooding depths of 1, 2, 4, and 6 cm, respectively, for the seeds sown on the soil surface. Fluroxypyr and MCPA herbicides provided 100% control of triquetrous murdannia at the 2- to 6-leaf stages; however, to achieve 100% control with bispyribac-sodium, MCPA+bentazone or MCPA+fluroxypyr, herbicides had to be applied by the 4-leaf stage. The results of this study could help in developing more sustainable and effective integrated weed management strategies for the control of triquetrous murdannia in rice fields in China.

Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 854-860 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Gurjeet Gill ◽  
Christopher Preston
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Field Experiments ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Factors Affecting ◽  
Control Programs ◽  
Buried Seed ◽  
Ph Range

Annual sowthistle has become more abundant under no-till systems in southern Australia. Increased knowledge of germination biology of annual sowthistle would facilitate development of effective weed control programs. The effects of environmental factors on germination and emergence of annual sowthistle seeds were examined in laboratory and field experiments. Seeds of annual sowthistle were able to germinate over a broad range of temperatures (25/15, 20/12, and 15/9 C day/night temperatures). Seed germination was favored by light; however, some germination occurred in the dark as well. Greater than 90% of seeds germinated at a low level of salinity (40 mM NaCl), and some seeds germinated even at 160 mM NaCl (7.5%). Germination decreased from 95% to 11% as osmotic potential increased from 0 to −0.6 MPa and was completely inhibited at osmotic potential greater than −0.6 MPa. Seed germination was greater than 90% over a pH range of 5 to 8, but declined to 77% at pH 10. Seedling emergence was the greatest (77%) for seeds present on the soil surface but declined with depth, and no seedlings emerged from a soil depth of 5 cm. In another experiment in which seeds were after-ripened at different depths in a field, seed decay was greater on the soil surface than at 2 or 5 cm depth. At the end of the growing season, there was a much greater persistence of buried seed (32 to 42%) than seeds present on the soil surface (8%). Greater persistence of buried seed could be due to dormancy enforced by dark in this species.

Factors Affecting Buffalobur (Solanum rostratum) Seed Germination and Seedling Emergence

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 521-525 ◽  
Author(s):  
Shouhui Wei ◽  
Chaoxian Zhang ◽  
Xiangju Li ◽  
Hailan Cui ◽  
Hongjuan Huang ◽  
...  
Keyword(s):  
Seed Germination ◽  
Light Exposure ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Distribution Area ◽  
Burial Depth ◽  
Weed Species ◽  
Continuous Darkness ◽  
Invasive Weed

Buffalobur is a noxious and invasive weed species native to North America. The influence of environmental factors on seed germination and seedling emergence of buffalobur were evaluated in laboratory and greenhouse experiments. The germination of buffalobur seeds occurred at temperatures ranging from 12.5 to 45 C, with optimum germination attained between 25 and 35 C. Buffalobur seeds germinated equally well under both a 14-h photoperiod and continuous darkness; however, prolonged light exposure (≥ 16 h) significantly inhibited the seed germination. Buffalobur seed is rather tolerant to low water potential and high salt stress, as germination was 28 and 52% at osmotic potentials of −1.1 MPa and salinity level of 160 mM, respectively. Medium pH has no significant effect on seed germination; germination was greater than 95% over a broad pH range from 3 to 10. Seedling emergence was higher (85%) for seeds buried at a soil depth of 2 cm than for those placed on the soil surface (32%), but no seedlings emerged when burial depth reached 8 cm. Knowledge of germination biology of buffalobur obtained in this study will be useful in predicting the potential distribution area and developing effective management strategies for this species.

Japanese Foxtail (Alopecurus japonicus) Management in Wheat in China: Seed Germination, Seedling Emergence, and Response to Herbicide Treatments

2017 ◽  
Vol 32 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Hengzhi Wang ◽  
Yizhao Huang ◽  
Lele Zhang ◽  
Weitang Liu ◽  
Jinxin Wang
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Integrated Approach ◽  
Growth Stages ◽  
Ph Values ◽  
Grass Weed ◽  
Different Growth Stages

AbstractLittle information is published related to seed germination and seedling emergence of Japanese foxtail, a troublesome annual grass weed widely distributed in winter wheat fields in China. Three Japanese foxtail populations were studied under laboratory and greenhouse conditions, to determine the effects of different environmental factors on seed germination or seedling emergence. Chemical control is absolutely necessary in integrated management, and efficacy of POST herbicides against different growth stages of Japanese foxtail was evaluated. Germination rate was 90% or more when temperature ranged from 5 to 25 C, with germination onset shortened as temperature increased. Light was not required for germination to occur. For pH values ranging from 5 to10 there was no effect on seed germination. Japanese foxtail seed germination was sensitive to osmotic stress and completely inhibited at an osmotic potential of -1.1 MPa. The ‘1513’ population of Japanese foxtail demonstrated tolerance to soil salinity, with 98% germination at 80 mM NaCl compared with 25 and 40% germination for populations ‘1532’ and ‘1544’, respectively. High amounts of crop residue (10 t ha−1) suppressed Japanese foxtail emergence 38 to 55%. Germination of seeds placed at 160 C for 5 min was completely inhibited for dry seeds, with a similar effect at 130 C for pre-soaked seeds. Seed burial in the soil from 0 to 4 cm had no effect on seedling emergence, but burial at 7 cm completely inhibited seedling emergence. POST herbicides mesosulfuron-methyl (13.5 g ai ha−1), clodinafop-propargyl (67.5 g ai ha−1), pyroxsulam (13.5 g ai ha−1), pinoxaden (67.5 g ai ha−1) and isoproturon (1125 g ai ha−1) reduced plant dry weight 80% or more when applied at three- to seven-leaf stage, but control declined with application at later growth stages. The information from this study helps to develop an integrated approach to Japanese foxtail management.

Seed Germination and Seedling Emergence of Synedrella (Synedrella nodiflora) in a Tropical Environment

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
David E. Johnson
Keyword(s):  
Seed Germination ◽  
Crop Residue ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Burial Depth ◽  
The Family ◽  
Synedrella Nodiflora ◽  
Annual Plant Species ◽  
Osmotic Potentials

Synedrella is a tropical annual plant species of the family Asteraceae that is widely distributed in many crops in nearly 50 countries. Experiments were conducted to determine the influence of various environmental factors on seed germination and seedling emergence of synedrella. Germination response was greater at 30/20 C and 35/25 C than at 25/15 C fluctuating day/night temperatures. Light stimulated germination; however, a small proportion of after-ripened seeds germinated in the dark. Seedling emergence was greatest (96%) for seeds placed on the soil surface but declined with increased seed burial depth. No seedlings emerged from a depth of 4 cm. Seedling emergence and seedling dry matter declined with the addition of crop residue to the soil surface; however, higher quantities of residue than those normally found in low-yield systems were required to result in substantial reductions in emergence. Seed germination was tolerant of moderate salt concentrations (40 to 100 mM sodium chloride) and a broad range of pH (4 to 10) but was sensitive to low osmotic potentials (< −0.8 MPa). The information gained from this study could help predict the invasion potential of this species and could lead to improved management strategies.

Sign in / Sign up

Export Citation Format

Share Document