Problems with using mean germination time to calculate rate of seed germination

2015 ◽  
Vol 63 (8) ◽  
pp. 631 ◽  
Author(s):  
Elias Soltani ◽  
Farshid Ghaderi-Far ◽  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
The Other ◽  
Seed Vigour ◽  
Or Groups ◽  
Germination Speed ◽  
Mean Germination Time ◽  
Treatment Comparisons ◽  
Time Spread ◽  
Mean Time

Seed scientists and other plant biologists are interested in the measurement of germination because seeds from different individuals, populations, seed lots and treatments can differ in germination percentages, rate (speed) and uniformity. Mean time to germination (MGT) is a measure of the rate and time-spread of germination; however, there is a problem with using this method to calculate germination rate. MGT does not show the time from the start of imbibition to a specific germination percentage. MGT has been used to compare specific pairs or groups of means and to evaluate seed vigour. However, it is not the real time to mean germination but just an index of germination speed. Using MGT is not correct for ANOVA, post-ANOVA or the other comparison tests, because it does not show time to a specific germination percentage. Thus, we recommend that t50 be used instead of MGT. The t50 has all benefits of MGT, but it does not have the problems of MGT in treatment comparisons.

scholarly journals Interruption of Seed Dormancy and In Vitro Germination of the Halophile Emerging Crop Suaeda edulis (Chenopodiaceae)

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 103
Author(s):  
Francyelli Regina Costa-Becheleni ◽  
Enrique Troyo-Diéguez ◽  
Alejandra Nieto-Garibay ◽  
Luis Alejandro Bustamante-Salazar ◽  
Hugo Sergio García-Galindo ◽  
...  
Keyword(s):  
Salinity Gradient ◽  
Germination Rate ◽  
Germination Percentage ◽  
In Vitro Germination ◽  
Best Response ◽  
Best Value ◽  
Germination Speed ◽  
Mean Germination Time ◽  
The Mean

Suaeda edulis (Flores Olvera & Noguez) is a halophile species that grows in saline environments, with concomitant difficulties to germinate and reproduce. Once a null germination under a salinity gradient or fresh water was observed, a plant-growth bioregulator (BioR) was applied to interrupt dormancy and improve germination in vitro. This BioR is composed of gibberellins and adjuvant regulators; and 12.5, 25.0, and 37.5 mg L−1 of gibberellins with immersion at 24, 48, and 72 h were assayed. Most of the normality and homoscedasticity tests were favorable, except in three of 24 cases. On the germination percentage (transformed values), the dose 25.0 mg L−1 reflected the highest values of 5.5 and 6.0 units at 48 and 72 h. For the mean germination time, the highest level of 37.5 mg L−1 at 24 h reflected the best response. For the germination rate, the best one was 25 mg L−1 at 48 h, reaching 12% per day, but for the germination speed coefficient, the best value was observed with 25.0 mg L−1 at 24 h. It was concluded that to improve germination of S. edulis seeds, it is necessary to assess a dose-gradient of gibberellins, starting at 25.0 mg L−1, with higher values to break dormancy.

scholarly journals GERMINATION AND POST-SEMINAL DEVELOPMENT OF Melaleuca alternifolia (MAIDEN & BETCHE) CHEEL

2020 ◽  
Vol 44 ◽  
Author(s):  
Daniel Teixeira Pinheiro ◽  
André Dantas de Medeiros ◽  
Paulo César Hilst ◽  
Antônio Lelis Pinheiro ◽  
Denise Cunha Fernandes dos Santos Dias
Keyword(s):  
Germination Rate ◽  
Seedling Development ◽  
The Other ◽  
Melaleuca Alternifolia ◽  
Seedling Morphology ◽  
X Ray ◽  
Germination Speed ◽  
Mean Time ◽  
Empty Seeds ◽  
The Ideal

ABSTRACT There is little information regarding the germination pattern, seed characterization, and seedling development of Melaleuca alternifolia. This study aimed to determine the ideal temperature for the germination of M. alternifolia seeds, as well as to characterize the seeds and the post-seminal development of the species. Three lots of M. alternifolia seeds were placed to germinate at 20, 25, 20-30, 20-35, 30, and 35 °C, with daily evaluations to determine germination rate, germination speed index (GSI), speed of germination (SG), and mean time for germination of 50% (t50) and 100% (t100) of seeds. The inner morphology of the seeds was evaluated through X-ray images and seedling morphology by photographs. Alternating temperatures (20-30 and 20-35 °C) led to germination rates higher than the other temperatures. The GSI had the lowest values at the constant temperature of 20 °C and the highest values at the constant 30 °C for all the lots. The SG was lowest at a temperature of 20 °C and the highest at the temperature of 35 °C. At alternating temperatures (20-30 and 20-35 °C), t50 was around 5 days and t100 reached 16 days. In conclusion, the alternating temperatures of 20-30 °C and 20-35 °C are recommended for germination of M. alternifolia, and final evaluation can be performed at 16 days after sowing. The inner structures of seeds could be visualized by X-ray analysis, and full seeds could be distinguished from empty seeds and impurities. Seeds exhibit epigeal germination and seedling development is stabilized after 30 days.

scholarly journals Biopriming with Seaweed Extract and Microbial-Based Commercial Biostimulants Influences Seed Germination of Five Abelmoschus esculentus Genotypes

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1327
Author(s):  
Gugulethu Makhaye ◽  
Adeyemi O. Aremu ◽  
Abe Shegro Gerrano ◽  
Samson Tesfay ◽  
Christian P. Du Plooy ◽  
...  
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Plant Growth Promoting Rhizobacteria ◽  
Germination Percentage ◽  
Abelmoschus Esculentus ◽  
Significant Interaction Effect ◽  
Plant Growth Promoting ◽  
Mean Germination Time ◽  
Coefficient Of Velocity ◽  
Time Spread

Seed germination is a crucial step in plant propagation, as it controls seedling production, stand establishment and ultimately crop yield. Approaches that can promote seed germination of valuable crops remain of great interest globally. The current study evaluated the effect of biostimulant (Kelpak® and plant-growth-promoting rhizobacteria—PGPR) biopriming on the seed germination of five (VI037996, VI046567, VI055421, VI050956, and VI033796) Abelmoschus esculentus genotypes. The germination responses of the bio-primed seeds were measured using six parameters, including final germination percentage (FGP), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), germination rate index (GRI), and time spread of germination (TSG). Biostimulant application significantly affected MGT (1.1–2.2 days), CVG (1.4–5.9), and TSG (1.2–3.0 days). Genotype also significantly influenced the TSG (1–3 days). Significant interaction effect of biostimulant treatment and genotype was evident on the FGP, GI, and GRI of the germinated seeds. The most noteworthy effect was demonstrated by Kelpak® (1:100) applied to genotype VI037996, with significantly improved FGP (82%), GI (238), and GRI (77%/day) when compared to the control. Overall, the current findings suggest the potential stimulatory effect of biostimulants (especially Kelpak®) on the germination of Abelmoschus esculentus seeds. However, this influence was strongly dependent on the type of genotype.

Chitosan coating on bean and maize seeds: release of agrochemical fungicide and post-storage condition

2021 ◽  
Vol 43 ◽  
Author(s):  
Nancy Araceli Godínez-Garrido ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Jorge Covarrubias-Prieto ◽  
Francisco Cervantes-Ortiz ◽  
Artemio Pérez-López ◽  
...  
Keyword(s):  
Seed Germination ◽  
Defense Mechanisms ◽  
Germination Rate ◽  
Storage Condition ◽  
Germination Percentage ◽  
Negative Effects ◽  
Retention Capacity ◽  
Chitosan Coating ◽  
Maize Seeds ◽  
Germination Speed

Abstract: Chitosan is a biopolymer obtained from deacetylation of chitin; it has multiple applications in agriculture as an antifungal, soil conditioner, inducer of defense mechanisms, fruits postharvest coating, leaves and seeds, among others. The objective in this research was to evaluate the effect of chitosan coatings mixed with fungicide (dithiocarbamate) on the germination and germination speed of bean and maize seeds in storage and to determine the retention capacity of the fungicide in the coated seeds under different times of imbibition. Two coating treatments at concentrations of 0.1 and 0.5% chitosan in water, two coatings treatments at 0.1 and 0.5% chitosan supplemented with 0.5% fungicide and a coating without chitosan using only 0.5% fungicide in water were used in bean and maize seed; and as control seeds imbibed in distilled water were used; after treatments, germination percentage and germination speed were determined, also fungicide release were determined at 0, 1, 2 and 6 h of imbibition, and the effect of storage time on germination and germination speed was determined at 30, 60, 90, 120, 150 and 180 days of storage at 4 °C and 45% relative humidity. The fungicide release effect was determined by inhibiting Fusarium oxysporum conidia germination. There were no negative effects of coatings on seed germination after storage. The treatment that provided both greater retention of the fungicidal agent and released it gradually, was 0.5% chitosan mixed with fungicide concentration. Chitosan coating seeds mixed with fungicide do not cause negative changes in seed germination or germination rate.

scholarly journals Phytotoxicity of Chitosan and SiO2 Nanoparticles to Seed Germination of Wheat (Triticum aestivum L.) and Barley (Hordeum vulgare L.) Plants

2017 ◽  
Vol 9 (2) ◽  
pp. 242-249 ◽  
Author(s):  
Faride BEHBOUDI ◽  
Zeinalabedin TAHMASEBI SARVESTANI ◽  
Mohamad Zaman KASSAEE ◽  
Seyed Ali Mohamad MODARES SANAVI ◽  
Ali SOROOSHZADEH
Keyword(s):  
Germination Rate ◽  
Dry Weight ◽  
Sio2 Nanoparticles ◽  
Triticum Aestivum L ◽  
Germination Percentage ◽  
Hordeum Vulgare L ◽  
Randomized Design ◽  
Direct Exposure ◽  
Contrast Exposure ◽  
Mean Germination Time

Plants such as wheat and barley that are strategically important crops need to be considered to develop a comprehensive toxicity profile for nanoparticles (NPs). The present study was aimed to investigate the effects of chitosan and SiO2 NPs on wheat and barley plants. Two factorial experiments (seeds priming and direct exposure) were performed based on a completely randomized design in four replications. Results showed that the seeds priming with the NPs had not significant effect on germination parameters such as Germination Percentage (GP), Germination Rate (GR), Germination Value (GV), Mean Germination Time (MGT), Pick Value (PV) and Mean Daily Germination (MDG). In contrast, exposure of the seeds to the NPs had significant effects on these parameters. In both experiments, treatments had significant effects on shoot, seedling, root length, fresh and dry weight, as well as vigor indexes as compared to the control. In most traits, the best concentration of NPs was 30 ppm, whereas applications of the NPs with 90 ppm displayed adverse effects on majority of the studied traits. According to these results, selectivity in applications of NPs with suitable concentration and method is essential for different plant species.  

scholarly journals SUPERAÇÃO DA DORMÊNCIA EM SEMENTES DE Plathymenia reticulata Benth.

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 317
Author(s):  
Cássio Do Prado Borges ◽  
Cheila Deisy Ferreira ◽  
Daniela Pereira Dias
Keyword(s):  
Electrical Conductivity ◽  
Germination Percentage ◽  
Lateral Side ◽  
Detergent Solution ◽  
Sodium Hypochlorite Solution ◽  
Percentage Germination ◽  
Dormancy Breaking ◽  
Germination Speed ◽  
Mean Germination Time ◽  
T1 And T2

Este trabalho objetivou avaliar a germinação e vigor de sementes de Plathymenia reticulata Benth. submetidas a diferentes tratamentos para superação de dormência. Os tratamentos testados foram: controle - sementes intactas (T0), escarificação mecânica com lixa d’água nº 60 (T1), desponte na região lateral do tegumento (T2), imersão em água fervente por 10 min (T3), em hipoclorito de sódio por 15 min (T4) e em solução com detergente por 15 min (T5). Foram determinados: peso de mil sementes, grau de umidade, porcentagem de germinação, índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), curva de embebição, teste da condutividade elétrica e comprimento da radícula. A porcentagem de germinação das sementes submetidas ao T1 e T2 foi estatisticamente igual (respectivamente, 90 e 88%) e superiores aos outros tratamentos testados (12%). As sementes expostas aos T1 e T2 apesentaram porcentagem de absorção de água superiores e em menor tempo, assim como maiores IVG e menores TMG, comparadas aos demais tratamentos. O comprimento das radículas não variou entre os tratamentos testados. A condutividade elétrica da solução com as sementes do T0 foi superior aos outros tratamentos testados. Sementes de P. reticulata expostas ao T1 e T2 apresentam maior germinação e vigor.Palavras-chave: germinação, índice de velocidade de germinação, teste de condutividade elétrica, vigor, vinhático. DORMANCY BREAKING OF Plathymenia reticulata Benth. SEEDS ABSTRACT:This study aimed to evaluate the germination and vigor of Plathymenia reticulata Benth. seeds submitted to different dormancy breaking treatments. Testing treatments were: control - intact seeds (T0); mechanical scarification with sandpaper n. 60 (T1), coating cutting in the lateral side of tegument (T2), immersion in boiling water during 10 min (T3), in sodium hypochlorite solution during 15 min (T4), and in detergent solution during 15 min (T5). Moisture content, 1000-seed weight, germination percentage, germination speed index (GSI), mean germination time (MGT), imbibition curve, electrical conductivity test, and radicle length were determined. Germination percentage to T1 and T2 were statistically equal (90 and 88 %, respectively) and higher than others treatments tested (12%). Seeds exposed to T1 and T2 also presented higher and faster water absorption percentage, when compared to the others treatments, as well as higher GSI, and lower MGT. The rootlets length did not vary among treatments tested. Electrical conductivity of intact seeds was higher than others treatments. P. reticulata seeds expose to T1 e T2 had highest germination percentage and vigor.Keywords: germination, germination speed index, electrical conductivity test, vigor, vinhático.

Perianth colour affects germination behaviour in wind-pollinated Salsola rubescens in Arabian deserts

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Ali A. El-Keblawy ◽  
Arvind Bhatt ◽  
Sanjay Gairola
Keyword(s):  
Salinity Tolerance ◽  
Germination Rate ◽  
Germination Percentage ◽  
Ecological Role ◽  
Light Requirement ◽  
Germination Speed ◽  
Germination Behaviour ◽  
Seeds Germination

Salsola rubescens Franch. is a wind-pollinated halophytic shrub that produces fruits with red and yellow winged perianths. Germinability of seeds from both fruit types was determined under various light, temperature, and salinity treatments. Red seeds, with and without winged perianths, were heavier than yellow seeds. Germination percentage and germination rate index (speed) were significantly affected by the perianth colour, presence of wings, and temperature and light of incubation and most of their interactions. Germination percentage was greater for yellow-winged seeds than for red-winged seeds. Wing removal significantly enhanced the germination percentage and germination speed in the two types. The presence of wings enhanced germination at lower temperatures, but wing absence enhanced germination at higher temperatures. Wing removal enhanced germination to a greater degree in yellow than in red seeds. There was no light requirement during germination of red-winged seeds, but yellow-winged seeds germinated significantly more in light than in darkness. Red-winged and dewinged seeds were more tolerant to salinity than yellow seeds. Removal of wings significantly increased salinity tolerance for seeds of both wing colours. It is concluded that the showy perianth colours have an ecological role in wind-pollinated plants in regulating dormancy and germination behaviour in the heterogeneous unpredictable hyperarid deserts.

scholarly journals Morphological and germination response variability in seeds of wild yellow gentian (Gentiana lutea L.) accessions from northwest Spain

Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 731-742 ◽  
Author(s):  
Félix Pérez-García ◽  
Federico Varela ◽  
M. Elena González-Benito
Keyword(s):  
Seed Germination ◽  
Water Content ◽  
Germination Rate ◽  
Seed Mass ◽  
Germination Percentage ◽  
Gentiana Lutea ◽  
Moist Chilling ◽  
Mean Germination Time ◽  
Wild Accessions ◽  
Seed Water Content

Gentiana lutea L. (yellow gentian, Gentianaceae) is an important medicinal plant under protection as endangered species in most European countries. The aim of this work was to evaluate variation in seed mass, seed water content, and seed germination among 56 wild accessions of G. lutea. The effect of gibberellic acid (GA3), putrescine, moist chilling, and level of ripeness of seeds on subsequent germination was also investigated. Seeds of G. lutea showed physiological dormancy (final germination percentages ranged from 0% to 11%, depending on the accession) and GA3 enhanced seed germination drastically in all the accessions. The highest germination (99%) of GA3-treated seeds was reached at 15 °C. Final germination percentage and germination rate (as expressed by mean germination time), as well as seed mass and seed water content, varied significantly among accessions. In general, 1 year moist chilling did not significantly enhance G. lutea seed germination. For most accessions, no significant differences were found between fully ripe seeds and less ripe seeds for seed water content, seed mass, and seed germination. Applications of GA3 were always most effective than those of putrescine for increasing seed germination.

scholarly journals Osmotic Seed Priming of Rudbeckia fulgida Improves Germination and Expands Germination Range

HortScience ◽  
1994 ◽  
Vol 29 (8) ◽  
pp. 868-870 ◽  
Author(s):  
Amy M. Fay ◽  
Mark A. Bennett ◽  
Steven M. Still
Keyword(s):  
Polyethylene Glycol ◽  
Germination Rate ◽  
Seed Priming ◽  
Germination Percentage ◽  
The Mean ◽  
Mean Time

Low-vigor seeds of black-eyed Susan (Rudbeckia fulgida Ait.) primed in aerated -1.3 MPa KNO3 for 7 days at 30C in darkness had double the total germination percentage at 30C and one-half the mean time of germination as nonprimed seeds. Priming the seeds in polyethylene glycol rather than KNO3 generally resulted in lower total germination percentage and longer mean time of germination. Osmotic priming increased total germination percentage and germination rate of seeds germinated at 21.9 to 32.2C, but the priming benefit on total germination percentage was greater at ≤27.6C. Total germination percentage of primed and nonprimed seeds was highest at 28.8 to 32.2C.

scholarly journals Evaluation of Seed Quality Attributes of Sorghum Germplasm Accessions from Eastern, Coastal and Nyanza Regions, Kenya

2020 ◽  
Vol 9 (3) ◽  
pp. 9
Author(s):  
C. W. Muui ◽  
R. M. Muasya ◽  
S. Nguluu ◽  
A. Kambura
Keyword(s):  
Food Security ◽  
Seed Quality ◽  
Germination Percentage ◽  
Seed Vigour ◽  
Subsistence Farmers ◽  
Germination Time ◽  
Vigour Index ◽  
Mean Germination Time ◽  
Handling Practices ◽  
Germplasm Accessions

Sorghum (Sorghum bicolor L.) is an important cereal crop in Kenya. Despite the crops importance, the yields attained by farmers in Eastern, Coastal and Nyanza regions of Kenya remain low. Access to good quality seeds of sorghum is one of the constraints facing the subsistence farmers. Good quality seed is important for increasing yield to attain food security. The aim of this study was to evaluate quality attributes of the seed used by farmers. A total of 108 germplasm accessions were obtained from 76 farmers. The seeds were tested for time and percentage of germination, seed vigour index, shoot and root dry weight. Data collected was subjected to analysis of variance. Means were separated using Fisher’s Least Significance Difference test at p ≤ 0.05. Seed samples of 26 accessions attained germination percentage below stipulated standards by Seeds and Plant Varieties Act CAP 326. Majority of seeds showed longer mean germination time with only nine accessions germinating in less than ten days. Seed vigour index was relatively high in most of the accessions, while biomass accumulation varied from high to very low among accessions. Though most of the seeds attained a high germination percentage, about 92% of seeds showed longer mean germination time. The environmental conditions in the fields, pre and post harvest handling practices impact on the seed quality hence the wide variability in germination percentage, germination time, seed vigour index and dry matter accumulation. Therefore the need to improve quality of seeds used by subsistence farmers by providing extension services on best pre and post harvest handling practices. Increasing production of sorghum in these regions will contribute significantly towards realizing food security. Further analysis could be carried out on genetic and sanitary quality aspects of the seeds planted by farmers in Eastern, Nyanza and Coastal regions.

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