scholarly journals Effect of Soil Temperature in the Emergence of Maize Seeds

2018 ◽  
Vol 11 (1) ◽  
pp. 479 ◽  
Author(s):  
Heloisa O. dos Santos ◽  
Renato C. C. Vasconcellos ◽  
Beatriz de Pauli ◽  
Raquel M. O. Pires ◽  
Elise M. Pereira ◽  
...  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Seedling Emergence ◽  
Genetic Material ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Department Of Agriculture ◽  
Maize Seeds ◽  
Germination Process ◽  
High And Low Temperatures

Temperature is one of the most important factors in the germination process, which influences the absorption of nutrients required for growth and development of the plant, germination uniformity, and seed vigor maintenance. Low temperatures can result in deformation of the leaves and the apex of the plant, and high temperatures hamper the development of them. The objective of this work was to evaluate the ideal temperature values for germination in each genetic material used, highlighting the most suitable for each condition. The experiment was conducted at the Central Seed Laboratory at the Department of Agriculture of the Lavras Federal University, where germination percentage, first germination count, seedling emergence and emergence speed were evaluated. The experimental design was completely randomized, with a factorial scheme of 4 × 5, in which it was analyzed four lines (L30, L64, L63, and L91) at five different germination temperatures (15, 20, 25, 30 and 35 ºC). An analysis of variance was done and for the comparison between means, the Scott Knott test was used, at a 5% probability. It can be observed that the lines L63 and L91 were more susceptible to low germination temperatures and lines L30 and L64 do not tolerate high temperatures. Also, the evaluation of temperature-controlled substrate germination proved to be a promising technique to identify tolerant and susceptible lines for germination in both high and low temperatures.

scholarly journals A Comparative Analysis of the Hybrid Maize (Zea mays L.) Seed Quality in China from 2013 to 2018

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 625
Author(s):  
Heqin Li ◽  
Haiwang Yue ◽  
Li Li ◽  
Chengfu Su ◽  
Xiaowen Zhang ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Seed Quality ◽  
Starch Content ◽  
Seedling Emergence ◽  
Principal Component ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Maize Seed ◽  
The Past ◽  
Hybrid Maize

In this study, a comparative analysis of seed quality indicators of 1196 hybrid maize seed samples from the main maize-producing areas in China from 2013 to 2018 was carried out. The results showed that the maize seed quality in China had changed obviously in the past six years, and was mainly as follows: The percentage of samples with coated seed in 2015–2018 was higher than 62.8% in 2013 and all exceeded 97%; the sample rate of packaging according to seed number was from 24.5% in 2013 to 58.6% in 2018, and the percentage of samples which met the prescribed quality standards was from 89.2% in 2013 to 98.4% in 2018. Principal component analysis indicated that standard germination energy (SGE), standard germination percentage (SGP), cold test germination percentage (CTGP), accelerated aging test germination percentage (AATGP), and mean field seedling emergence (FSE) were the primary predictors of seed germination and seedling emergence. Meanwhile, combining other statistical methods, regression models of SGE, SGP, CTGP, and AATGP were established to predict the field seedling emergence. Furthermore, seed bulk density and total starch content were correlated with seed vigor, which needs to be further studied. This study offered a theoretical basis and data support to better understand the changes of maize quality in China over the past six years, and provided an important reference to further improve the maize seed quality in the future.

scholarly journals Caracterization of seed germination of Zephyranthes sylvatica (Mart.) Baker (Amarilidacea)

2014 ◽  
Vol 36 (2) ◽  
pp. 178-185
Author(s):  
Mayara Wesley da Silva ◽  
Laise Guerra Barbosa ◽  
José Eduardo Santos Barboza da Silva ◽  
Keylan Silva Guirra ◽  
Diego Rangel da Silva Gama ◽  
...  
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Seedling Emergence ◽  
Primary Root ◽  
Seed Vigor ◽  
Optimum Temperature ◽  
Salt Stress Tolerance ◽  
Germination Process ◽  
The Ideal

Zephyranthes sylvatica is a beautiful lily, endemic from the Brazilian Caatinga. Although it has a great ornamental potential, little is known about this species, especially regarding its seeds germination process. Aiming to characterize the germination of Z. sylvatica seeds, we studied its imbibition curve, optimum temperature and substrate for germination and seedling emergence, osmotic and salt stress tolerance, as well as the tolerance to frosting/ defrosting, which indicates long term cryostorage potential. The germination of Z. sylvatica presents a triphasic model of imbibition, in which the primary root protrusion occurs after 72 hours of imbibition. The ideal conditions for evaluating seed germination of Z. sylvatica is 25 ºC, in paper rolls. These seeds are highly tolerant to osmotic stress, but not to salt stress. Z. sylvatica seeds can be cryopreservated without loss of germination and seed vigor.

scholarly journals Effect of Seed Priming on Germination Properties and Seedling Establishment of Cowpea (Vigna sinensis)

2011 ◽  
Vol 3 (4) ◽  
pp. 113-116 ◽  
Author(s):  
Hamdollah ESKANDARI ◽  
Kamyar KAZEMI
Keyword(s):  
Laboratory Tests ◽  
Low Cost ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Laboratory Data ◽  
Seed Priming ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Seedling Vigor ◽  
Contributing Factors

Early emergence and stand establishment of cowpea are considered to be the most important yield-contributing factors in rainfed areas. Laboratory tests and afield experiment were conducted in RCB design in 2011 at a research farm in Ramhormoz, Iran, to evaluate the effects of hydropriming (8, 12 and 16 hours duration) and halo priming (solutions of 1.5% KNO3 and 0.8% NaCl) on seedling vigor and field establishment of cowpea. Analysis of variance of laboratory data showed that hydropriming significantly improved germination rate, seed vigor index, and seedling dry weights. However, germination percentage for seeds primed with KNO3 and non-primed seeds were statistically similar, but higher than those for NaCl priming. Overall, hydropriming treatment was comparatively superior in the laboratory tests. Invigoration of cowpea seeds by hydropriming and NaCl priming resulted in higher seedling emergence and establishment in the field, compared to control and seed priming with KNO3. Seedling emergence rate was also enhanced by priming seeds with water, suggesting that hydropriming is a simple, low cost and environmentally friendly technique for improving seed and seedling vigor of cowpea.

scholarly journals Correlation between vigor by accelerated aging at pre-sowing and soybean seedling emergence in the field

2021 ◽  
Vol 42 (2) ◽  
pp. 455-470
Author(s):  
Vanderléia Mathias ◽  
◽  
Cileide Maria Medeiros Coelho ◽  
Keyword(s):  
Exposure Time ◽  
Seedling Emergence ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Growing Seasons ◽  
Accelerated Aging Test ◽  
Physiological Quality ◽  
Field Emergence

Although the accelerated aging test is widely used to determine seed vigor, there are methodological variations in seed exposure time at 41 °C. Therefore, the objective was to indicate the most appropriate seed exposure time to segregate lots that also exhibits a correlation with seedling emergence in the field, and establish vigor levels using the aforementioned test. Soybean seed samples were collected at pre-sowing, representing 100 lots in the 2016/2017 growing season and 125 lots in the 2017/2018 season from different warehouses in 4 regions of Santa Catarina state (SC). Physiological quality was evaluated by germination, accelerated aging (24 and 48 h at 41 °C) and field emergence tests. The results were submitted to descriptive statistical analysis and Pearson’s correlation analysis (p < 0.05). The rank sum index, associated with the Scott-Knott clustering method, was used to classify physiological quality. The average germination percentage was 90 and 91% in the 2016/2017 and 2017/2018 growing seasons, respectively. Vigor obtained an average of 86 (2016/2017) and 85% (2017/2018), when seeds were submitted to accelerated aging for 48 h, and 89% (both seasons) for 24 h. In regard to field emergence, the average was 85 and 80% in the 2016/2017 and 2017/2018 growing seasons, respectively. Considering the 225 lots, the greatest correlation with field emergence was observed in vigor - 48 h (r = 0.71 p < 0.05). Rank sum classification made it possible to establish vigor-based categories, whereby batches with over 85% vigor by 48-h accelerated aging were classified as high vigor, 70 to 84% medium vigor, and under 70% low vigor.

scholarly journals Seeding Month and Seed Soaking Affect Buffalograss Establishment

HortScience ◽  
1993 ◽  
Vol 28 (9) ◽  
pp. 902-903 ◽  
Author(s):  
Jack Fry ◽  
Ward Upham ◽  
Larry Leuthold
Keyword(s):  
Low Temperatures ◽  
Seedling Emergence ◽  
Growing Season ◽  
Field Studies ◽  
Complete Coverage ◽  
Seed Soaking ◽  
High And Low Temperatures

Field studies were conducted in consecutive years to evaluate the influence of seeding month and seed soaking on buffalograss [Buchloë ductyloides (Nutt.) Engelm.] establishment, as measured by percentage of coverage and seedling emergence. In 1991, plots where `Sharp's Improved' buffalograss burrs were seeded in May, June, or July exhibited complete coverage 7 weeks after seeding (WAS). Between Apr. and Sept. 1992, mean high and low temperatures were ≈ 3C cooler than in 1991, and seeding in June or July resulted in >95% coverage 9 WAS. In the same year, seeding in April or May required 12 to 13 weeks for complete coverage. Buffalograss seeded in August exhibited <25% coverage by the end of the first growing season. Soaking buffalograss burrs in water before seeding resulted in the emergence of >30% more seedlings 2 WAS compared with nonsoaked burrs and increased coverage by up to 18% on selected rating dates 3 to 13 WAS. However, complete coverage occurred only ≈ week sooner where soaked vs. nonsoaked burrs were planted.

scholarly journals Seedling image analysis and traditional tests to evaluate onion seed vigor

2017 ◽  
Vol 39 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Nayara Roberto Gonçalves ◽  
Silvio Moure Cicero ◽  
Haynna Fernandes Abud
Keyword(s):  
Electrical Conductivity ◽  
Image Analysis ◽  
Imaging System ◽  
Seedling Emergence ◽  
Accelerated Aging ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Seedling Length ◽  
Onion Seed ◽  
Emergence Percentage

Abstract: The aim of this study was to verify the possibility of using computerized seedling image analysis to detect differences in vigor among onion seed lots and to compare this analysis with traditional vigor tests. We used five seed lots of two onion cultivars, Bella Catarina and Bella Vista. The Seed Vigor Imaging System (SVIS®) software was used to process the seedling images and assess seedling length and vigor through seedling uniformity and growth indexes. These determinations were compared to traditional tests used to evaluate onion seed vigor: germination percentage and first germination count, seedling emergence percentage and emergence speed, accelerated aging, and electrical conductivity. Results showed that vigor differences among onion seed lots can be identified using the SVIS® in a manner similar to traditional vigor tests; assessments should be performed at five days after sowing.

Temperature Tolerance in Young Pacific Salmon, Genus Oncorhynchus

1952 ◽  
Vol 9 (6) ◽  
pp. 265-323 ◽  
Author(s):  
J. R. Brett
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Oncorhynchus Tshawytscha ◽  
Prolonged Exposure ◽  
Pacific Salmon ◽  
Vertical Gradient ◽  
Temperature Tolerance ◽  
Preferred Temperature ◽  
High And Low Temperatures ◽  
Temperature Responses

Lethal limits of high and low temperatures were determined for the young of five species of Pacific salmon, the spring (Oncorhynchus tshawytscha), the pink (O. gorbuscha), the sockeye (O. nerka), the chum (O. keta) and the coho (O. kisutch).For acclimation temperatures ranging from 5° to 24 °C. significant differences between species in their resistance to high temperatures was obtained. The spring and coho were most resistant. The pink and chum salmon were least resistant, and the sockeye was distinguishable from the latter two by greater resistance for prolonged exposure to high temperatures. No species could tolerate temperatures exceeding 25.1 °C. when exposed for one week.A fanning-out of the opercula was shown to be directly correlated with the onset of death from a low temperature. By use of this criterion mixed lethal effects at low temperatures were demonstrated and found to be influenced by the size of the fish and by the salinity of the water. None of the species could withstand temperatures lower than 4 °C. when acclimated to 20 °C. and above. When taken from holding troughs as low as 5 °C., coho and sockeye could not tolerate long exposure (four days) to 0 °C.In a vertical gradient little difference in preferred temperature was observed, either between species or for different acclimation temperatures. The 12° to 14 °C. stratum was the region of greatest concentration.Specific differences in temperature responses are in keeping with taxonomic and ecological distinctions.

Vibrational properties of BaFe11.1Sc0.9O19 hexaferrite at high and low temperatures

2020 ◽  
Vol 34 (33) ◽  
pp. 2050381
Author(s):  
A. I. Mammadov ◽  
N.T. Dang ◽  
R. Z. Mehdiyeva ◽  
À. V. Trukhanov ◽  
R. E. Huseynov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperatures ◽  
Low Temperatures ◽  
Structural Phase ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Powder Samples ◽  
Raman Modes ◽  
High And Low Temperatures

[Formula: see text] hexaferrite compound was synthesized, the crystal structure was studied by the X-ray diffraction method. Powder samples were prepared from the mark “analytical grade” oxides [Formula: see text], [Formula: see text] and carbonate BaCO3. It was found that under normal conditions and at room temperatures, the crystal structure of this compound has hexagonal symmetry with the P63mmc space group. The lattice parameters correspond to the values: [Formula: see text] and [Formula: see text]. Atomic dynamics of [Formula: see text] hexaferrite in the range of low temperatures of [Formula: see text] and high temperatures of [Formula: see text] were studied. As a result of the analysis of the spectra obtained by the Raman spectroscopy method, it was determined that the structural phase transition does not occur in this compound over a wide temperature range [Formula: see text]. At the room temperature, the obtained Raman modes are observed at both low and high temperatures.

scholarly journals Lifetime Prediction of Polymers: To Bet, or Not to Bet—Is This the Question?

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1383 ◽  
Author(s):  
Ignazio Blanco
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Polymeric Materials ◽  
Real Data ◽  
Degradation Process ◽  
Decomposition Temperature ◽  
Successful Completion ◽  
Initial Decomposition Temperature ◽  
Activation Energy Of Degradation ◽  
High And Low Temperatures

Polymers are a great and very important category of organic compounds that have changed our lifestyle. In the last eighty years, we have used them for the most varied applications, and from the first structural ones we began to investigate their durability, which can be fatal in the successful completion of the application for which the material was designed. Over the last thirty years, the environmental problems related to the disposal of polymers that have completed their lifecycle have begun to arise, and the need to foresee their end of life has become increasingly urgent. In this manuscript, the reliability of the lifetime predictions of polymeric materials is faced with comparing measurements obtained at low temperature with those carried out at high temperatures, in the molten state. The obtained data were treated by a well-established kinetics model and discrepancies were observed in the two different conditions (high and low temperatures), which led to a mismatching between expected and real data. A correction of the data extrapolated from measurements obtained at high temperatures, by using a novel equation which takes into account the induction period (IP) of the degradation process, is proposed. Considerations about the useful parameters, namely initial decomposition temperature (Ti), activation energy of degradation (Ea), and glass-transition temperature (Tg), to be used for making predictions, are also carried out.

Germination, Emergence, Vegetative Growth and Flowering of Two Silvergrasses, Vulpia bromoides (L.) S.F. Gray and V. myuros (L.) C.C. Gmel

1984 ◽  
Vol 32 (2) ◽  
pp. 165 ◽  
Author(s):  
SP Dillon ◽  
F Forcella
Keyword(s):  
Vegetative Growth ◽  
Low Temperatures ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Measured Characteristic ◽  
Rates Of Growth ◽  
Depth Of Burial

Effect of temperature and light on seed germination percentage and rate, depth of burial and seasonality on seedling emergence, and temperature and photoperiod on both vegetative growth and flowering were examined for two species of silvergrass in Australia. Maximum germination percentage was high for both taxa and occurred over a broad range of temperatures. In darkness, both optimum temperature for germination and germination rate were higher for V. myuros than for V. bromoides. In light, optimum temperature was similar for both species, although V. myuros maintained its higher rate. In addition, light doubled the range of temperatures over which the two species were able to germinate. Emergence of both taxa was retarded if seeds were buried below surficial depths but was consistently higher for V. myuros than for V. bromoides at all depths. Upon fulfilling an after-ripening requirement of 2-3 months, fresh seed could germinate and emerge in the field at any season but most seed germinated with the first substantial summer or early autumn rain. Vegetative growth of both species was stimulated initially by high temperatures and long photoperiods but, subsequently, growth was much greater at low temperatures and short photoperiods. This changing response with age to temperature and photoperiod corresponds to expected changes in field environments as plants age naturally V. rnyuros usually maintained higher rates of growth than V. bromoides. Low temperatures and short photoperiods also were required for flowering, particularly for V. myuros. Flowering was the only measured characteristic for which V. bromoldes had greater environmental tolerance than V. myuros. These characteristics of silvergrass relate to their incidence in direct drilled crops in the higher rainfall zones of southern Australia, compared to their relative absence in conventionally sown crops.

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