Performance of carrot seeds possessing different germination rates within a seed lot

1988 ◽  
Vol 110 (1) ◽  
pp. 93-99 ◽  
Author(s):  
W. E. Finch-Savage ◽  
C. I. McQuistan
Keyword(s):  
Environmental Conditions ◽  
Coefficient Of Variation ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Seedling Performance ◽  
Controlled Conditions ◽  
Carrot Seed ◽  
The Relationship ◽  
Fluid Drilling

SummaryThe relationship between germination rate within a carrot seed lot and subsequent seedling performance was studied in four seed lots of different viability. Seedling performance was assessed using slope tests conducted under controlled conditions and in the field following fluid drilling under a range of environmental conditions. Germination rate within a seed lot was positively related to vigour measured by slope tests, percentage emergence and seedling weight, and was negatively related to the spread of emergence times (In variance days) and the coefficient of variation (c.v.) of seedling weights. Sowing seeds selected as fast germinating resulted in greater seedling emergence percentages over a range of environmental conditions than when sowing seeds selected as slowly germinating.

Effects of Seed Carriers on Seedling Establishment after Fluid Drilling

1980 ◽  
Vol 16 (2) ◽  
pp. 153-160 ◽  
Author(s):  
R. J. Darby
Keyword(s):  
Physical Properties ◽  
Sodium Alginate ◽  
Environmental Conditions ◽  
Seedling Establishment ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Moisture Stress ◽  
Crop Species ◽  
Synthetic Clay ◽  
Fluid Drilling

SUMMARYSix products possessing suitable physical properties as fluid carriers for pre-germinated seed were assessed for their effects on seedling emergence. Both glasshouse and field experiments measured the carriers' performance on eight crop species at varying extrusion rates and under different environmental conditions. Synthetic clay or polyacrylate increased seedling emergence by 10% compared with the sodium alginate control. Seedling emergence was least affected by moisture stress when synthetic clay was used as the carrier.

A field study of seed dispersal and seedling performance in the invasive exotic vine Vincetoxicum rossicum

2005 ◽  
Vol 83 (9) ◽  
pp. 1181-1188 ◽  
Author(s):  
David Ladd ◽  
Naomi Cappuccino
Keyword(s):  
Seed Quality ◽  
Seedling Emergence ◽  
Great Lakes Basin ◽  
Old Field ◽  
Seedling Performance ◽  
Performance Variables ◽  
Vincetoxicum Rossicum ◽  
Invasive Exotic ◽  
The Relationship ◽  
Herbaceous Perennial

The exotic vine Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae) is a major natural-areas pest throughout the Great Lakes Basin. Colonization of new areas by this herbaceous perennial occurs by comose wind-dispersed seeds. Previous experiments suggested a trade-off between seed dispersability and seed quality: smaller seeds dispersed farther but were less likely to emerge and seedlings were smaller when grown in competition with turf grasses in the greenhouse. We examined dispersability by trapping seeds at distances of 0–60 m from a seed source, and we assessed seedling performance by sowing seeds of known weight in an old field. Smaller seeds travelled significantly farther than larger seeds; however, the relationship between weight and distance dispersed was weak (r2 = 0.043). Large seeds were significantly more likely to emerge, and the seedlings survive and grow taller; however, the relationships between seed size and these performance variables were also weak (r2 ≤ 0.02). The dispersability–quality tradeoff is unlikely to play an important role in V. rossicum spread at the local scale, as even large seeds are competent dispersers and even seedlings from small seeds are capable of becoming established. Seedlings from polyembryonic seeds were more likely to successfully establish than seeds from which a single seedling emerged. The high seedling emergence (50% for seeds planted above ground; 72% for those buried to a depth of 1 cm) and survivorship (71%–100%, depending on embryony) are likely to contribute to the success of this species.

scholarly journals Individual quality of life and the environment – towards a concept of livable areas for persons with disabilities in Poland

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Izabela Grabowska ◽  
Radosław Antczak ◽  
Jan Zwierzchowski ◽  
Tomasz Panek
Keyword(s):  
Quality Of Life ◽  
Environmental Conditions ◽  
Basic Research ◽  
Research Problem ◽  
Individual Characteristics ◽  
Living Conditions ◽  
Special Focus ◽  
Persons With Disabilities ◽  
The Relationship

Abstract Background The United Nations Convention on the Rights of Persons with Disabilities [1] highlights the need to create proper socioeconomic and political conditions for persons with disabilities, with a special focus on their immediate living conditions. According to the Convention, these conditions should be built to ensure that persons with disabilities have the potential to enjoy a high quality of life (QoL), and this principle is reflected in the notion of livable areas. The crucial aspect of this framework is the relationship between the individual QoL and the environment, broadly understood as the socioeconomic as well as the technical conditions in which persons with disabilities function. Methods The basic research problem was to assess the relationship between individual QoL for the population with disabilities as a dependent variable and livability indicators as independent variables, controlling for individual characteristics. The study used a dataset from the EU-SILC (European Union Statistics on Income and Living Conditions) survey carried out in 2015 in Poland. The research concept involved several steps. First, we created a variable measuring the QoL for the entire population with disabilities. To measure the multidimensional QoL, we used Sen’s capability approach as a general concept, which was operationalized by the MIMIC (multiple indicators multiple causes) model. In the second step, we identified the livability indicators available in the official statistics, and merged them with survey data. Finally, in the last step, we ran the regression analysis. We also checked the data for the nested structure. Results We confirmed that the general environmental conditions, focused on creating livable areas, played a significant role in shaping the QoL of persons with disabilities; i.e., we found that the higher the level of the local Human Development Index, the higher the quality of life of the individuals living in this area. This relationship held even after controlling for the demographic characteristics of the respondents. Moreover, we found that in addition to the general environmental conditions, the conditions created especially for persons with disabilities (i.e., services for this group and support for their living conditions) affected the QoL of these individuals. Conclusions The results illustrate the need to strengthen policies aimed at promoting the QoL of persons with disabilities by creating access to community assets and services that can contribute to improving the life chances of this population.

scholarly journals Effects of Cultivar and Ethanol Disinfection on Aseptic Germination of Loquat (Eriobotrya japonica) Seeds

HortScience ◽  
2017 ◽  
Vol 52 (7) ◽  
pp. 941-945
Author(s):  
Kunkun Li ◽  
Weiqi Dong ◽  
Yun Zhao ◽  
Hongxia Xu ◽  
Junwei Chen ◽  
...  
Keyword(s):  
Detrimental Effect ◽  
Germination Rate ◽  
Fruit Tree ◽  
Final Concentration ◽  
Eriobotrya Japonica ◽  
Seedling Height ◽  
Disinfection Procedure ◽  
Aba Content ◽  
Subtropical Fruit ◽  
The Relationship

Loquat (Eriobotrya japonica Lindl.) is an economically important subtropical fruit tree, originating and commercially produced mainly in China and Japan. The aseptic seed germination of 13 loquat cultivars, including 9 white-fleshed cultivars and 4 red-fleshed ones, was studied, and the relationship between the germination rate and the content of endogenous ABA in seeds was explored. The germination rate and the seedling height at 80 days after sowing of white-fleshed cultivars were generally higher than that of red-fleshed ones. The ABA content in seeds was generally lower in white-fleshed cultivars, and the ABA content negatively correlated with the germination rate at 80 days after sowing. A moderate detrimental effect of 75% ethanol disinfection on aseptic germination of loquat seeds was observed, especially, for the cultivar Dahongpao, and the germination rate and seedling height were reduced by around half and one-third, respectively. The addition of plant preservative mixture (PPM) to the germination medium at a final concentration of 25 mg·L−1 effectively controlled contamination when the 75% ethanol disinfection procedure was omitted.

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.

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.

Improvement of carrot crop establishment by combining seed treatments with increased seed-bed moisture availability

1990 ◽  
Vol 115 (1) ◽  
pp. 75-81 ◽  
Author(s):  
W. E. Finch-Savage ◽  
W. G. Pill
Keyword(s):  
Soil Moisture ◽  
Surface Structure ◽  
Untreated Control ◽  
Seedling Emergence ◽  
Seed Treatments ◽  
Crop Establishment ◽  
Shoot Weight ◽  
Germinating Seeds ◽  
Mean Time ◽  
Fluid Drilling

SUMMARYIn studies of carrots sown on three dates at Wellesbourne in 1986, mean time to seedling emergence and spread of times to seedling emergence of untreated and fluid-drilled seeds increased as seed-bed moisture at sowing decreased. These differences were not observed with irrigation before sowing.Osmotic priming increased the percentage of seeds with emerged radicles at the time of fluid drilling from 17% in the untreated control to 56%. Irrespective of seed-bed moisture, time to emergence was shorter from primed germinating seeds than from germinating seeds, both treatments giving earlier seedling emergence than untreated seeds. Seedling shoot weight was greater from treated than from untreated seeds.Seed-bed characteristics on unirrigated plots had no effect on seedling emergence when soil moisture was adequate but, where soil moisture was limiting, rolling the seed bed to increase capillarity resulted in 79% emergence compared with the 67% average from seed beds that were not rolled. Application of a soil conditioner to stabilize the seed-bed surface structure generally improved emergence when rain fell soon after sowing. The results suggested that a combination of seed-bed and seed treatments can significantly improve the predictability of crop establishment of carrots on different dates.

The relationship between pellet size and the quantity of imidacloprid applied to sugar beet pellets and the consequences for seedling emergence

1997 ◽  
Vol 16 (2) ◽  
pp. 187-192 ◽  
Author(s):  
A.M. Dewar ◽  
F. Westwood ◽  
K.M. Bean ◽  
L.A. Haylock ◽  
R. Osborne
Keyword(s):  
Sugar Beet ◽  
Seedling Emergence ◽  
Pellet Size ◽  
The Relationship

Seed size as a determinant of germination rate in Crepis tectorum (Asteraceae): evidence from a seed burial experiment

1996 ◽  
Vol 74 (4) ◽  
pp. 568-572 ◽  
Author(s):  
Stefan Andersson
Keyword(s):  
Seed Size ◽  
Germination Rate ◽  
Local Population ◽  
Seed Viability ◽  
Seed Burial ◽  
Small Seed ◽  
Crepis Tectorum ◽  
Winter Annual ◽  
Selection For ◽  
The Relationship

The present study of the winter annual Crepis tectorum examines the relationship between seed (achene) size and the extent to which seeds resist germination during the year of their production. I carried out two seed burial experiments, one at an outcrop site occupied by a small-seeded population, and another in an experimental garden with soil from the same field site, with seeds representing the local population and a segregating generation of a cross between two other populations. Using logistic regression with data corrected for seed viability, I found an association between small seed size and failure to germinate in the first autumn. The small seed size characterizing many outcrop populations may have evolved as a response to selection for delaying germination in a habitat subject to unpredictable droughts during the growth season. Keywords: Crepis tectorum, germination, seed bank, seed size.

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